General Malaise
General malaise is a nonspecific feeling of overall discomfort, illness, or lack of well-being that often accompanies the onset of various acute and chronic diseases.
General Malaise
General malaise is a subjective, non-specific symptom defined as a feeling of overall discomfort, unease, lack of well-being, or "not feeling right" that is difficult for the patient to localize or describe precisely. The term derives from the Old French mal (= bad) + aise (= ease), literally meaning "bad ease" or ill-at-ease.
It is not a diagnosis but rather a symptom — and more importantly, it is a constitutional symptom, meaning it reflects a systemic process affecting the whole body rather than any single organ. It sits in the same family as fatigue, lethargy, weakness, and tiredness, though these terms are not identical:
| Term | Key Distinction |
|---|---|
| Malaise | A vague sense of feeling unwell; qualitative — "I just don't feel right" |
| Fatigue / Tiredness | A quantitative lack of energy or endurance; "I'm exhausted" |
| Lethargy | Drowsiness or sluggishness with reduced arousal |
| Weakness | Actual loss of muscle power (objective vs. subjective) |
| Asthenia | a- (without) + sthenos (strength) — generalized weakness/debility |
In practice, patients use these terms interchangeably, so the clinician's job is to clarify what the patient actually means — are they tired (fatigue)? Sleepy (somnolence)? Weak (myopathy, neuropathy)? Or just feeling generally unwell (malaise)? [1][2]
Why Malaise Matters
Malaise is the body's "check engine light." It is a non-specific alarm signal indicating that something systemic is going on — from a simple viral upper respiratory infection to occult malignancy, autoimmune disease, or chronic organ failure. The broad differential is precisely what makes it a high-yield exam topic: you need a systematic framework to approach it.
- Malaise is one of the most common presenting complaints in primary care and general practice
- In Hong Kong, it is frequently encountered in General Out-Patient Clinics (GOPCs) and emergency departments, particularly among:
- Middle-aged and elderly patients (due to accumulation of comorbidities)
- Young adults (psychosocial stressors, viral illness, mood disorders)
- "Tiredness" or "fatigue" (which overlaps substantially with malaise) accounts for 5–10% of all primary care consultations in Western studies; similar figures are seen in HK
- Women > men in most epidemiological studies (~2:1), possibly due to higher rates of depression, anaemia (menstrual losses), thyroid disease, and functional somatic syndromes
- Many cases are self-limiting (viral illnesses), but a proportion will have serious underlying pathology — hence the need for a structured approach
Rather than risk factors for malaise itself (since nearly any illness can cause it), think of risk factors that increase the probability of serious underlying cause:
| Category | Risk Factors |
|---|---|
| Age | Extremes of age — elderly (occult malignancy, organ failure), neonates (sepsis) |
| Comorbidities | Diabetes, CKD, chronic liver disease, heart failure, HIV, autoimmune disease |
| Medications | Polypharmacy, beta-blockers, sedatives, chemotherapy, statins |
| Lifestyle | Inappropriate lifestyle and psychosocial factors [1], sedentary behaviour, poor sleep hygiene, shift work |
| Psychosocial | Stress and anxiety, social isolation, bereavement, occupational burnout |
| Nutritional | Iron-deficient diet, veganism (B12), alcohol excess, eating disorders |
| Infections | Recent travel (tropics), IV drug use, sexual history, animal contact, immunosuppression |
| Family history | Haemochromatosis, autoimmune diseases, hereditary anaemias |
Anatomy and Physiology of the "Feeling Unwell" Response
To understand malaise from first principles, you need to understand sickness behaviour — an evolutionary conserved, coordinated neurobiological response to infection and inflammation.
-
Peripheral trigger: Infection, tissue injury, malignancy, or autoimmune activation triggers innate immune cells (macrophages, dendritic cells) to release pro-inflammatory cytokines: IL-1β, IL-6, TNF-α, IFN-α/γ.
-
Signal to brain: These cytokines reach the CNS via:
- Circumventricular organs (areas lacking a blood–brain barrier, e.g. organum vasculosum of the lamina terminalis)
- Vagal afferents (abdominal vagal paraganglia sense local cytokines and relay signals to the nucleus tractus solitarius → hypothalamus)
- Active transport across the BBB
- Endothelial activation — brain endothelial cells produce prostaglandins (PGE₂) in response to circulating cytokines
-
Central processing: In the hypothalamus and brainstem, cytokine signalling:
- Alters thermoregulation → fever (via PGE₂ resetting the hypothalamic set-point)
- Reduces motivation and reward → anhedonia, apathy (via ↓dopaminergic signalling in nucleus accumbens)
- Promotes sleep and inactivity → lethargy (↑NREM sleep drive)
- Suppresses appetite → anorexia
- Activates the HPA axis → cortisol release → further modulates immune and metabolic activity
- Activates the sympathetic nervous system → tachycardia, sweating
-
Subjective experience: The patient reports "malaise" — that vague, uncomfortable feeling of being unwell. It is the conscious perception of sickness behaviour.
Why does malaise occur? It is an adaptive response: by making you feel terrible, the body forces you to rest, conserve energy for the immune response, and withdraw from social interaction (reducing spread of infection). It is a feature, not a bug.
Malaise also occurs without overt inflammation through:
- Metabolic derangement: Electrolyte imbalances (↓Na⁺, ↓K⁺, ↑Ca²⁺, uraemia) directly impair cellular function and CNS neurotransmission → subjective malaise
- Hormonal deficiency: Hypothyroidism (↓metabolic rate → fatigue), adrenal insufficiency (↓cortisol → inability to mount stress response → profound malaise), hypogonadism
- Tissue hypoxia: Anaemia (↓O₂ carrying capacity), heart failure (↓cardiac output), respiratory failure → insufficient O₂ delivery to tissues → fatigue, malaise
- Psychological mechanisms: Depression involves serotonin/norepinephrine dysfunction → overlap with sickness behaviour pathways; chronic stress → HPA axis dysregulation → cortisol resistance → chronic low-grade inflammation
- Sleep disruption: Fragmented or insufficient sleep → ↑IL-6, TNF-α (yes, sleep deprivation itself is pro-inflammatory!) → malaise
Etiology (Focus on Hong Kong Context)
The causes of general malaise are vast. A practical framework from Murtagh's Diagnostic Strategies [1] categorizes them into:
- Probability diagnoses (common)
- Serious disorders not to be missed
- Pitfalls (often missed)
- Rarities
A. Probability Diagnoses (Most Common Causes)
These are the diagnoses you should think of first when a patient presents with tiredness/malaise:
- Pathophysiology: Chronic psychological stress → sustained HPA axis activation → cortisol dysregulation → central fatigue, sleep disruption, and sickness behaviour-like state. Anxiety also → hyperventilation, muscle tension, hypervigilance → exhaustion.
- Very common in HK given high work pressures, competitive academic environment, housing stress
- Often co-exists with insomnia, which compounds fatigue
- Sedentary lifestyle → deconditioning → reduced exercise tolerance perceived as fatigue
- Poor sleep hygiene, excessive screen time, shift work
- Dietary factors: skipped meals, excess refined carbohydrates → reactive hypoglycaemia → postprandial fatigue
- Excess caffeine → disrupted sleep → daytime malaise
- Alcohol: even moderate intake disrupts sleep architecture (↓REM) → unrefreshing sleep
- Pathophysiology: ↓serotonin, ↓norepinephrine, ↑inflammatory cytokines → overlapping neural circuits with sickness behaviour → fatigue, anhedonia, psychomotor retardation
- Prevalence 2.9% in HK [3], but underdiagnosed — particularly "masked" depression [1] where somatic complaints (fatigue, malaise, pain) dominate the presentation without overt sadness
- Key: always screen for mood symptoms when evaluating malaise — "masked" depression is often missed [1]
- The most common acute cause of malaise — virtually any viral infection (URTI, gastroenteritis, etc.) causes cytokine-mediated sickness behaviour
- In HK: seasonal influenza, COVID-19, EBV (infectious mononucleosis in young adults), hepatitis viruses are important
- Post-viral fatigue: malaise persisting weeks to months after resolution of acute infection; if > 6 months → consider chronic fatigue syndrome
- Pathophysiology: persistent immune activation, ↑IL-6, mitochondrial dysfunction, autonomic dysregulation
- Obstructive sleep apnoea (OSA): very common in HK, especially with rising obesity rates. Repeated upper airway collapse during sleep → fragmented sleep → daytime somnolence, unrefreshing sleep, malaise
- Pathophysiology: recurrent hypoxia-reoxygenation → oxidative stress → systemic inflammation → fatigue; plus sleep fragmentation → ↓slow-wave sleep → impaired physical recovery
- Other sleep disorders: insomnia (often comorbid with depression/anxiety [4]), periodic limb movement disorder, circadian rhythm disorders (shift workers)
B. Serious Disorders Not to Be Missed
These are the red flag diagnoses — less common but potentially life-threatening:
- Cardiac arrhythmia: AF, sick sinus syndrome, heart block → ↓effective cardiac output → fatigue, malaise, presyncope. Often insidious in elderly
- Cardiomyopathy: Dilated cardiomyopathy → ↓CO → tissue hypoperfusion → fatigue. May present with malaise long before overt heart failure symptoms [5]
- Incipient congestive cardiac failure (CCF): Early heart failure often presents with exertional fatigue and malaise before classical dyspnoea, oedema. Pathophysiology: ↓CO → activation of RAAS and SNS → sodium/water retention, but initially just reduced exercise capacity and malaise [5]
- Hidden abscess: Intra-abdominal (subphrenic, pelvic, hepatic), dental, cerebral — can smoulder with malaise and low-grade fever for weeks
- HIV/AIDS: Seroconversion illness causes malaise, fever, rash, lymphadenopathy; later stages → chronic malaise from immunodeficiency and chronic inflammation. Must be considered in HK (rising MSM transmission rates)
- Hepatitis B and C / others: Extremely relevant in HK (HBV carrier rate ~7–8%). Chronic hepatitis → low-grade liver inflammation → fatigue, malaise. HCV also important but less prevalent in HK [6]
- Tuberculosis: HK is an intermediate TB burden area (incidence ~60/100,000). Chronic malaise, night sweats, low-grade fever, weight loss are classic constitutional symptoms [7]
- Any malignancy can present with malaise as the initial symptom — due to:
- Cytokine production by tumour (TNF-α, IL-6, IFN-γ → "cancer cachexia")
- Paraneoplastic syndromes
- Anaemia of chronic disease
- Direct organ dysfunction
- In HK context: lung cancer (commonest cancer death), colorectal cancer, hepatocellular carcinoma (HBV-related), nasopharyngeal carcinoma (especially in Southern Chinese), haematological malignancies [8]
- Constitutional symptoms (malaise, weight loss, night sweats, fever) in a haematological malignancy context are called "B symptoms" and indicate advanced disease [8]
- Anaemia: Multiple causes — iron deficiency (menstrual loss, GI bleeding), B12/folate deficiency, anaemia of chronic disease, thalassaemia (very common in HK — α-thal carrier rate ~3–4%, β-thal ~2–3%). ↓Hb → ↓O₂ delivery → fatigue, malaise, exertional dyspnoea [8]
- Haemochromatosis: Hereditary (HFE gene) or secondary iron overload → deposition in liver, pancreas, heart, joints. Early symptoms: fatigue, malaise, arthralgia. More common in Caucasians but not absent in HK Chinese. Classic triad: liver disease, diabetes, skin pigmentation ("bronze diabetes") [1]
C. Pitfalls (Often Missed)
These are causes that clinicians frequently overlook:
- As above — patients present with somatic complaints (malaise, pain, GI symptoms) without volunteering mood symptoms. The clinician must actively screen.
- Lactose intolerance: Very common in East Asians (~80–90% prevalence of lactase non-persistence) → bloating, abdominal discomfort, diarrhoea → chronic GI distress → fatigue and malaise
- Other food intolerances: FODMAPs, histamine intolerance
- Not to be confused with food allergy (IgE-mediated)
- Pathophysiology: Autoimmune reaction to gliadin (component of gluten) → villous atrophy in small intestine → malabsorption → iron/folate/B12 deficiency → anaemia → fatigue, malaise
- Traditionally considered rare in Asia but increasingly recognized
- Extra-intestinal manifestations (fatigue, anaemia, osteoporosis) may dominate over GI symptoms ("silent coeliac disease")
- Lyme disease: Caused by Borrelia burgdorferi, transmitted by Ixodes ticks. Rare in HK but important to consider in returned travellers. Post-treatment Lyme disease syndrome → chronic fatigue, malaise, arthralgia
- Tuberculosis: Already mentioned — a pitfall because chronic malaise may be the only presenting feature before classical respiratory symptoms develop
D. Additional Important Causes (Hong Kong Context)
Beyond Murtagh's framework, the following deserve emphasis:
| Condition | Pathophysiology of Malaise | HK Relevance |
|---|---|---|
| Hypothyroidism | ↓T3/T4 → ↓basal metabolic rate → ↓energy production → fatigue, cold intolerance, weight gain, constipation. Most common endocrine cause of fatigue | Common, especially autoimmune (Hashimoto's) in women |
| Hyperthyroidism | ↑metabolic rate → ↑energy expenditure → exhaustion despite hyperactivity; also → weight loss, tremor, anxiety | Graves' disease common in young Asian women |
| Adrenal insufficiency | ↓cortisol → inability to mount stress response → profound fatigue, hypotension, hypoglycaemia; ↓aldosterone → hyponatraemia, hyperkalaemia | Rare but must not miss; secondary AI from chronic steroid use more common |
| Diabetes mellitus | T2DM: insulin resistance → impaired glucose utilization → fatigue; also → osmotic symptoms (polyuria, polydipsia), dehydration. Often asymptomatic at dx with long Hx of fatigue [9] | Prevalence ~10% in HK [9], massive burden |
| Hypercalcaemia | ↑Ca²⁺ → ↓neuronal excitability → fatigue, malaise, confusion, constipation. Causes: primary hyperparathyroidism, malignancy | "Stones, bones, groans, moans, and psychic overtones" |
| Hypogonadism | ↓testosterone (men) or ↓oestrogen (women) → fatigue, ↓libido, mood changes | Consider in men with metabolic syndrome, women with premature ovarian failure |
- Chronic kidney disease (CKD): Uraemia → accumulation of uraemic toxins → central fatigue, nausea, anorexia, malaise. Also → anaemia (↓EPO) → tissue hypoxia. Very common in HK (high rates of diabetic nephropathy, hypertensive nephrosclerosis)
- Electrolyte derangements: hyponatraemia, hypokalaemia, hypermagnesaemia can all cause malaise
- Chronic liver disease: Regardless of cause (HBV, HCV, NAFLD, alcohol) → hepatic dysfunction → impaired detoxification, altered amino acid metabolism, accumulation of ammonia → fatigue, malaise. NAFLD is the hepatic manifestation of metabolic syndrome [6] — increasingly common in HK with rising obesity rates
- NASH: may present with fatigue, malaise and vague RUQ discomfort [6]
- SLE: Non-specific systemic upset early on, e.g. general malaise, arthralgia, myalgia, low-grade fever [10]. Very important in HK (Orientals have higher prevalence than Caucasians) [11]
- Rheumatoid arthritis: Chronic systemic inflammation → fatigue, malaise alongside joint symptoms
- Sjogren's syndrome: Fatigue is reported by >70% of patients
- Mixed connective tissue disease (MCTD): Non-specific systemic upset early on, e.g. general malaise, arthralgia, myalgia, low-grade fever → these symptoms make early diagnosis difficult [10]
- Polymyalgia rheumatica (PMR): Elderly patients with proximal muscle pain/stiffness, fatigue, malaise, ↑ESR. Important — responds dramatically to steroids
- Acute leukaemia: General fatigue in majority of patients, often precedes diagnosis for months [8]. Malaise + pallor + infections + bruising → think bone marrow failure
- Lymphoma: B symptoms (fever, night sweats, weight loss) + lymphadenopathy + malaise
- Myeloproliferative neoplasms: Primary myelofibrosis — severe fatigue as most common presenting symptom [8]; PV, ET also present with fatigue
- Chronic leukaemia (CLL/CML): Insidious fatigue, malaise, weight loss
Many medications cause malaise/fatigue as a side effect:
- Beta-blockers: ↓heart rate → ↓CO → fatigue; also cross BBB → central fatigue, depression
- Statins: myalgia/myopathy → fatigue (due to mitochondrial CoQ10 depletion)
- Antihypertensives: ACE inhibitors, CCBs, diuretics
- Psychotropics: SSRIs, benzodiazepines, antipsychotics (sedation)
- Chemotherapy: nearly universal fatigue
- Antihistamines: especially first-generation (cross BBB → sedation)
- Opioids: central sedation
- Defined as persistent or relapsing unexplained fatigue lasting ≥ 6 months, not due to ongoing exertion, not substantially relieved by rest, resulting in substantial reduction in activities
- Pathophysiology: poorly understood — likely involves immune dysregulation, autonomic dysfunction, mitochondrial dysfunction, neuroinflammation
- Post-infectious trigger recognized (EBV, COVID-19 → "long COVID" overlaps substantially with CFS/ME)
- Diagnosis of exclusion — must rule out all other organic and psychiatric causes first
- Highly relevant in 2025–2026 HK context
- Persistent fatigue, malaise, cognitive dysfunction ("brain fog"), exertional intolerance lasting ≥ 3 months after SARS-CoV-2 infection
- Pathophysiology: viral persistence, autoimmunity, endothelial dysfunction, microthrombi, autonomic dysregulation
A useful clinical classification uses a systems-based approach cross-referenced with Murtagh's framework:
Another practical classification by tempo of onset:
| Tempo | Duration | Likely Causes |
|---|---|---|
| Acute (days) | < 2 weeks | Viral infection, acute medical illness (ACS, PE), acute drug effect, sepsis, electrolyte derangement |
| Subacute (weeks) | 2–12 weeks | Post-viral, occult infection (TB, abscess), new medication, early depression, undiagnosed diabetes |
| Chronic (months–years) | > 12 weeks | Depression, hypothyroidism, CKD, chronic liver disease, CFS/ME, malignancy, autoimmune disease, sleep disorders |
Clinical Features
A. Symptoms (with Pathophysiological Basis)
The symptom of malaise itself is non-specific, so the clinical approach focuses on associated symptoms that point toward the underlying cause. When taking history, systematically ask about:
- Fever: Indicates infection or inflammatory process → cytokine-mediated thermogenesis (PGE₂ → ↑hypothalamic set-point)
- Pattern matters: intermittent (abscess, lymphoma), continuous (TB), relapsing (malaria, brucellosis)
- Night sweats: Drenching sweats requiring change of bedclothes → TB, lymphoma, endocarditis, brucellosis, HIV
- Pathophysiology: Cytokine-driven thermoregulatory resetting — fever peaks and then the set-point resets downward → compensatory sweating to dissipate heat, often during sleep
- Weight loss: Unintentional > 5% body weight over 6–12 months → malignancy, hyperthyroidism, TB, DM, malabsorption, depression, adrenal insufficiency
- Pathophysiology: ↑catabolic state (TNF-α → "cachectin"), ↓appetite, ↑metabolic rate, malabsorption
- Anorexia: Loss of appetite → liver disease, CKD (uraemia), malignancy, depression, adrenal insufficiency
- Pathophysiology: Cytokines (IL-1β, TNF-α) act on hypothalamic feeding centres → ↓appetite
Cardiovascular:
- Exertional dyspnoea, orthopnoea, PND → heart failure (why? ↓CO → pulmonary congestion → ↑hydrostatic pressure → interstitial oedema → impaired gas exchange → dyspnoea)
- Palpitations → arrhythmia
- Peripheral oedema → right heart failure, nephrotic syndrome
- Chest pain → ACS, pericarditis, myocarditis
Respiratory:
- Cough → infection, malignancy, ILD
- Haemoptysis → TB, lung cancer, PE
- Progressive dyspnoea → ILD, COPD, anaemia
GI:
- Nausea/vomiting → uraemia, hepatitis, hypercalcaemia, adrenal crisis
- Diarrhoea → infection, IBD, coeliac disease, hyperthyroidism
- Abdominal pain → hepatitis, pancreatitis, abscess
- Jaundice → hepatitis, haemolysis, biliary obstruction
Neurological:
- Headache → intracranial infection, space-occupying lesion, giant cell arteritis (elderly + malaise + temporal headache → urgent ESR)
- Cognitive changes → hypothyroidism, B12 deficiency, uraemia, hepatic encephalopathy, delirium [2]
- Paraesthesia → B12 deficiency (subacute combined degeneration), DM neuropathy
Musculoskeletal:
- Joint pain/stiffness → autoimmune (RA, SLE, MCTD), reactive arthritis, viral arthritis
- Arthralgia with malaise → think connective tissue disease, viral infection [10]
- Proximal myalgia → PMR, dermatomyositis, statin-related myopathy, hypothyroidism
Skin:
- Rash → viral exanthem, SLE (malar rash), drug reaction, erythema nodosum (prodrome: fatigue, fever, malaise, arthralgia [12])
- Pallor → anaemia
- Jaundice → liver disease, haemolysis
- Skin hyperpigmentation → Addison's disease (↑ACTH → ↑MSH → melanocyte stimulation), haemochromatosis
Urogenital:
- Polyuria/polydipsia → DM, hypercalcaemia, diabetes insipidus
- Dysuria/frequency → UTI
- Menorrhagia → iron deficiency anaemia
Psychological:
- Onset: Acute (infection, drug), gradual (endocrine, malignancy, CKD)
- Duration: Days (self-limiting viral), weeks-months (chronic disease)
- Diurnal variation: Worse in morning (depression — classically worse in early morning with early morning waking); worse as day progresses (physical deconditioning, adrenal insufficiency)
- Intermittent vs. continuous: Intermittent (relapsing-remitting autoimmune), continuous progressive (malignancy, organ failure)
- Relationship to exertion: Exacerbated by exertion (cardiac, respiratory, anaemia); no clear relationship (depression, hypothyroidism); worsened by post-exertional malaise (CFS/ME — pathognomonic feature)
Following the standard HPC structure [2]:
- Associating symptoms: Constitutional symptoms (fever, chills, night sweats, weight loss, malaise itself)
- Systemic enquiry: Screen ALL systems as above
- Risk factors:
- Travel history, occupation, sexual history, IV drug use, animal contact, medication [1]
- Dietary history, alcohol/substance use
- Sun exposure (vitamin D if deficient)
- Functioning: Exercise tolerance, ADLs, sleep quality, mood
- Treatment: Previous investigations, treatments tried, response
B. Signs (with Pathophysiological Basis)
Physical examination in a patient with malaise should be thorough and systematic, looking for clues to underlying cause:
| Sign | What It Suggests | Pathophysiology |
|---|---|---|
| Pallor | Anaemia | ↓Hb → ↓red colour of blood perfusing skin/mucous membranes |
| Jaundice | Liver disease, haemolysis | ↑unconjugated bilirubin (haemolysis) or ↑conjugated bilirubin (hepatic/obstructive) deposited in sclera and skin |
| Cachexia | Malignancy, chronic disease | TNF-α (cachectin) → ↑protein catabolism, ↑lipolysis, ↓appetite |
| Skin hyperpigmentation | Addison's disease, haemochromatosis | Addison's: ↓cortisol → ↓negative feedback → ↑ACTH (cleaved from POMC which also yields MSH) → melanocyte stimulation. Haemochromatosis: iron deposition in skin |
| Moon face, central obesity, striae | Cushing's syndrome | ↑cortisol → ↑gluconeogenesis, ↑lipolysis (limbs) + ↑lipogenesis (trunk/face), protein catabolism (striae) |
| Dry skin, coarse hair, periorbital oedema | Hypothyroidism | ↓T3/T4 → ↓metabolic rate → accumulation of glycosaminoglycans in dermis → myxoedema |
| Tremor, lid lag, exophthalmos | Hyperthyroidism | ↑sympathetic activation; exophthalmos = retro-orbital inflammation (Graves'-specific) |
- Fever: Infection, malignancy, autoimmune (always check temperature!)
- Tachycardia at rest: Anaemia (compensatory ↑CO to maintain O₂ delivery), thyrotoxicosis, dehydration, sepsis, heart failure
- Bradycardia: Hypothyroidism (↓metabolic demand → ↓HR), heart block, drugs (beta-blockers)
- Hypotension: Adrenal insufficiency (↓cortisol → ↓vascular tone; ↓aldosterone → volume depletion), sepsis, dehydration, heart failure
- Postural hypotension: Autonomic neuropathy (DM), adrenal insufficiency, dehydration, Parkinson's
| Sign | What It Suggests | Pathophysiology |
|---|---|---|
| Lymphadenopathy | Infection, lymphoma, metastatic cancer, autoimmune | Reactive hyperplasia (infection/autoimmune) or neoplastic infiltration |
| Glossitis / angular stomatitis | B12/folate/iron deficiency | ↓nutrients needed for rapidly dividing mucosal epithelial cells → atrophy [8] |
| Oral ulcers | SLE, Behçet's, Crohn's, B12 deficiency | Autoimmune mucosal inflammation, nutritional deficiency |
| Thyroid enlargement | Thyroid disease | Goitre (hypo- or hyperthyroidism, thyroiditis, malignancy) |
| Dental caries / abscess | Occult infection source | Dental infection → bacteraemia → endocarditis, abscess |
| Temporal artery tenderness | Giant cell arteritis | Granulomatous vasculitis of medium/large arteries → tenderness, ischaemia |
| Sign | What It Suggests | Pathophysiology |
|---|---|---|
| Displaced apex beat | Cardiomyopathy, LV dilatation | Ventricular remodelling → enlarged LV displaces apex laterally/inferiorly |
| Gallop rhythm (S3/S4) | Heart failure | S3: rapid ventricular filling into volume-overloaded ventricle; S4: atrial contraction against stiff ventricle |
| New murmur | Endocarditis, valvular disease | Turbulent flow across damaged/vegetated valve |
| Peripheral oedema | Heart failure, nephrotic, hepatic failure | ↑hydrostatic pressure (HF), ↓oncotic pressure (hypoalbuminaemia) |
| Raised JVP | Right heart failure, PE, pericardial tamponade | ↑right atrial pressure → transmitted back to jugular veins |
| Sign | What It Suggests | Pathophysiology |
|---|---|---|
| Hepatomegaly | Hepatitis, malignancy (metastasis/HCC), heart failure, haemochromatosis, NAFLD | Inflammatory swelling, neoplastic infiltration, congestion (RHF → ↑hepatic venous pressure) |
| Splenomegaly | Infection (EBV, malaria), haematological malignancy, portal hypertension, autoimmune haemolysis | Reticuloendothelial hyperplasia, extramedullary haematopoiesis, congestion |
| Ascites | Cirrhosis, malignancy, heart failure | Portal hypertension → ↑splanchnic hydrostatic pressure; hypoalbuminaemia → ↓oncotic pressure |
| Abdominal mass | Malignancy, abscess | Tumour growth, pus collection |
| Sign | What It Suggests | Pathophysiology |
|---|---|---|
| Malar rash | SLE | Immune complex deposition in dermis → complement activation → inflammation |
| Erythema nodosum | Sarcoidosis, TB, IBD, streptococcal infection, drug reaction | Delayed-type hypersensitivity reaction [12] → septal panniculitis |
| Petechiae / purpura | Thrombocytopenia, DIC, leukaemia | ↓platelet count or function → failure to plug microvascular breaches → extravasation of RBCs into skin |
| Koilonychia | Iron deficiency | ↓iron → abnormal nail matrix keratinization → thin, concave nails |
| Clubbing | Lung cancer, ILD, IE, IBD, cirrhosis, cyanotic heart disease | Mechanism debated — VEGF, platelet-derived growth factor deposited in nail bed; digital vasodilation |
| Splinter haemorrhages | Infective endocarditis, vasculitis | Microemboli/immune complex deposition in nail-bed capillaries |
| Raynaud's | CTD (scleroderma, MCTD, SLE) | Vasospasm of digital arteries → episodic digital ischaemia |
- Slow-relaxing reflexes: Hypothyroidism (↓metabolic rate → slowed muscle relaxation)
- Peripheral neuropathy: DM, B12 deficiency, uraemia, alcohol
- Proximal myopathy: Cushing's, hypothyroidism, vitamin D deficiency, dermatomyositis, statin-related
- Altered mental status / confusion: Delirium [2] — consider if malaise accompanies acute confusion in elderly (precipitated by infection, drugs, metabolic derangement, dehydration)
The Malaise 'Deep Dive' Rule
When a patient says "I just feel generally unwell" and you find nothing on initial assessment, resist the urge to dismiss it. Go back and re-examine: check temperature, look at the conjunctivae for pallor, palpate for lymphadenopathy, examine the abdomen carefully (hepatosplenomegaly?), check skin for rashes, and do a rectal examination if indicated. Many serious diagnoses (leukaemia, endocarditis, Addison's) were discovered only because someone did a thorough exam on a patient with "just malaise."
Common Exam Trap
Do not forget "masked" depression [1] — a patient presenting with fatigue, malaise, multiple somatic complaints, and no overt sadness. If you do not actively screen for depression (PHQ-9, ask about anhedonia and low mood), you will miss this extremely common diagnosis. Similarly, hypothyroidism in an elderly patient can perfectly mimic depression — always check TFTs.
| Category | Condition | Key Distinguishing Features | Key Investigation |
|---|---|---|---|
| Psychiatric | Depression | Low mood, anhedonia, sleep/appetite disturbance, diurnal variation | PHQ-9, clinical assessment |
| Psychiatric | Anxiety | Worry, restlessness, palpitations, hyperventilation | GAD-7, clinical assessment |
| Lifestyle | Poor sleep/lifestyle | Identifiable lifestyle factors, normal investigations | Sleep diary, clinical Hx |
| Infection | Acute viral | Acute onset, fever, rhinitis/pharyngitis, self-limiting | Usually clinical |
| Infection | Post-viral | Following acute infection, lasting weeks-months | Diagnosis of exclusion |
| Infection | TB | Chronic cough, night sweats, weight loss, contact Hx | CXR, sputum AFB/culture |
| Infection | HIV | Risk factors, lymphadenopathy, recurrent infections | HIV Ag/Ab combo test |
| Infection | HBV/HCV | RUQ discomfort, jaundice, risk factors | HBsAg, anti-HCV |
| Endocrine | Hypothyroidism | Cold intolerance, weight gain, constipation, dry skin | TSH, fT4 |
| Endocrine | DM | Polyuria, polydipsia, weight loss, recurrent infections | Fasting glucose, HbA1c |
| Endocrine | Adrenal insufficiency | Hypotension, hyperpigmentation, hyponatraemia | Short Synacthen test, 9am cortisol |
| Haematological | Iron deficiency anaemia | Pallor, koilonychia, menorrhagia/GI bleeding | CBC, iron studies |
| Haematological | B12/folate deficiency | Glossitis, neuropathy, macrocytosis | Serum B12, folate, MCV |
| Haematological | Leukaemia | Pallor, bruising, infections, hepatosplenomegaly | CBC with differential, blood film |
| Cardiac | Heart failure | Dyspnoea, oedema, orthopnoea, ↑JVP | BNP/NT-proBNP, Echo |
| Cardiac | Arrhythmia | Palpitations, presyncope, irregular pulse | ECG, Holter monitor |
| Hepatic | Chronic liver disease | Jaundice, spider naevi, palmar erythema, ascites | LFTs, hepatitis serology |
| Renal | CKD | Nausea, pruritus, nocturia, oedema | RFT (↑creatinine, ↑urea) |
| Autoimmune | SLE | Malar rash, arthralgia, photosensitivity, serositis | ANA, anti-dsDNA, C3/C4 |
| Malignancy | Any | Weight loss, night sweats, lymphadenopathy, mass | CT, biopsy, tumour markers |
| Other | Haemochromatosis | Liver disease, DM, skin pigmentation, arthropathy | Ferritin, transferrin sat, HFE gene |
| Other | CFS/ME | Post-exertional malaise, unrefreshing sleep, > 6 months | Diagnosis of exclusion |
High Yield Summary
Definition: General malaise = non-specific constitutional symptom of feeling unwell; reflects systemic process (cytokine-mediated sickness behaviour).
Top Causes (Murtagh's Probability Diagnoses) [1]:
- Stress and anxiety
- Inappropriate lifestyle and psychosocial factors
- Depression
- Viral / post-viral infection
- Sleep-related disorders (e.g. sleep apnoea)
Serious Not to Miss [1]: Cardiac (arrhythmia, cardiomyopathy, incipient CCF), Infection (hidden abscess, HIV/AIDS, hepatitis B and C, TB), Cancer, Anaemia, Haemochromatosis
Pitfalls [1]: Masked depression, Food intolerance, Coeliac disease, Chronic infection (Lyme disease, TB)
HK-Relevant Priorities: HBV (7–8% carrier), TB (intermediate burden), thalassaemia trait, NPC, rising T2DM/metabolic syndrome/NAFLD, depression
Pathophysiology: Pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) → brain via circumventricular organs/vagal afferents → hypothalamic sickness behaviour (fever, fatigue, anorexia, malaise) = adaptive response to conserve energy for immune response
Clinical Approach: Clarify symptom → systematic associated symptoms → constitutional review → systems review → thorough exam (don't skip lymph nodes, abdomen, skin) → targeted investigations based on clinical pointers
Red Flags: Unintentional weight loss, night sweats, persistent fever, lymphadenopathy, new mass, progressive symptoms, abnormal blood counts, age > 50 with new fatigue
Active Recall - General Malaise
[1] Lecture slides: murtagh merge.pdf (p99 — Tiredness/chronic fatigue) [2] Senior notes: Ryan Ho Fundamentals.pdf (p5 — History taking; p325 — Delirium) [3] Senior notes: Ryan Ho Psychiatry.pdf (p155 — Depressive Disorders; p202 — Somatic Symptom Disorder) [4] Senior notes: Ryan Ho Psychiatry.pdf (p222 — Insomnia) [5] Senior notes: Ryan Ho Cardiology.pdf (p165 — Myocarditis); Ryan Ho Critical Care.pdf (p22 — Cardiogenic Shock) [6] Senior notes: Ryan Ho GI.pdf (p206 — Acute Liver Failure; p309 — NAFLD) [7] Lecture slides: murtagh merge.pdf (p53 — Prolonged fever) [8] Senior notes: Ryan Ho Haemtology.pdf (p29 — B12 deficiency; p53 — AML; p60 — ALL; p78 — Primary Myelofibrosis) [9] Senior notes: Ryan Ho Endocrine.pdf (p77 — Type 2 DM; p117 — Obesity) [10] Senior notes: Ryan Ho Rheumatology.pdf (p86 — MCTD; p69 — SLE) [11] Senior notes: Ryan Ho Rheumatology.pdf (p69 — SLE epidemiology) [12] Senior notes: Ryan Ho Rheumatology.pdf (p157 — Erythema Nodosum)
Differential Diagnosis of General Malaise
The differential diagnosis of general malaise is enormous — arguably the broadest in all of medicine — because malaise is a non-specific constitutional symptom that can accompany virtually any systemic disease. The key challenge for the clinician is not to list every possible disease, but to structure your thinking so you move efficiently from "I feel generally unwell" to a working diagnosis.
The approach here uses three complementary frameworks layered together:
- Murtagh's Diagnostic Strategy — a primary-care probability framework (probability → serious → pitfalls → rarities) [1]
- Systems-based differential — to ensure nothing is missed organ-by-organ
- Tempo-based differential — acute vs. subacute vs. chronic, because timing alone eliminates huge chunks of the DDx
This is essentially a pre-test probability triage — what is the most likely, what must you not miss, and what do people often overlook?
Murtagh's Rule for Fatigue/Malaise
In general practice, the probability diagnoses (stress/anxiety, lifestyle factors, depression, viral/post-viral, sleep disorders) [1] account for the vast majority of cases. But you must always actively exclude the "serious not to miss" category — particularly anaemia, cancer, cardiac failure, and chronic infection — before settling on a benign explanation.
Framework 2: Systems-Based Differential Diagnosis
Below is a comprehensive systems-based DDx. For each system, I explain why that disease produces malaise, tying back to the cytokine–brain axis and metabolic pathophysiology discussed in Part 1.
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Depression [1][6] | ↓Serotonin/NE → overlapping neural circuits with sickness behaviour; chronic HPA axis activation → neuroinflammation, ↑IL-6/TNF-α | Low mood, anhedonia, sleep disturbance, appetite change, guilt, ↓concentration; "masked" depression if somatic features dominate [1]. Prevalence 2.9% in HK [6] |
| Anxiety / GAD [1][7] | Chronic hyperarousal → muscular tension, sleep disruption, exhaustion; hyperventilation → respiratory alkalosis → paraesthesia, dizziness, fatigue | Free-floating persistent anxiety, somatic features (palpitations, sweating, muscle tension, sleep disturbance); tiredness is a common accompaniment but never the most prominent feature [7] |
| Somatic symptom disorder [8] | Amplification of normal bodily sensations via dysfunctional cognitive-emotional processing; comorbid depression/anxiety contribute | ≥1 somatic symptom causing distress + excessive thoughts/worry/behaviours about symptoms; high healthcare utilization, doctor-shopping [8]; symptoms often include fatigue, pain, GI, CVS/resp, neurological complaints [8] |
| Adjustment disorder | Acute psychological stress → HPA dysregulation, sleep disruption | Onset ≤3 months of identifiable stressor; symptoms do not meet full criteria for depression; resolves when stressor is removed [6] |
| Substance use disorders | Alcohol → disrupted sleep architecture, hepatotoxicity, nutritional deficiency; opioids → central sedation; stimulant withdrawal → fatigue | Detailed drug/alcohol history essential; collateral history |
Key Pitfall
"Masked" depression [1] is listed as a pitfall because patients present with somatic complaints (fatigue, pain, GI symptoms) without volunteering mood symptoms. If you do not actively ask about anhedonia and low mood, you will miss it. Similarly, somatic symptom disorder [8] requires you to recognize disproportionate health concern — but remember, under DSM-5, a coexistent medical condition does NOT exclude this diagnosis.
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Viral / post-viral infection [1][9] | Acute: cytokine storm (IL-1β, IL-6, TNF-α, IFN) → sickness behaviour. Post-viral: persistent immune activation, mitochondrial dysfunction | Acute coryza: malaise, low-grade fever, rhinitis, pharyngitis, self-limiting in ~10 days [9]. Post-viral: fatigue persisting weeks–months after resolution |
| HIV/AIDS [1] | Seroconversion: massive viraemia → cytokine release → flu-like illness. Chronic: persistent immune activation, opportunistic infections, wasting | Risk factors (MSM, IVDU, unprotected sex), seroconversion illness (fever, rash, pharyngitis, lymphadenopathy), later: weight loss, recurrent infections |
| Hepatitis B and C [1][3] | Chronic hepatic inflammation → circulating cytokines, impaired hepatic detoxification → central fatigue | HK HBV carrier rate ~7–8%. May have RUQ discomfort, jaundice, hepatomegaly. Generalized malaise is a prominent feature of liver failure [3] |
| Tuberculosis [1][10] | Chronic granulomatous inflammation → TNF-α, IFN-γ, IL-12 → sustained sickness behaviour; tissue destruction | Insidious onset of non-specific symptoms including fever, malaise, weight loss, chronic ill-health [10]; cryptic TB: may be erroneously attributed to other co-existent chronic disease [10]; HK intermediate burden area |
| Infectious mononucleosis (EBV) [9] | Massive T-cell expansion + cytokine release (especially IFN-γ) → profound fatigue | Prodrome: low-grade fever, malaise, headache → then severe malaise, pharyngitis, lymphadenopathy, hepatosplenomegaly; fatigue may persist for up to 6 months in 10% [9] |
| Hidden abscess [1] | Walled-off infection → continuous low-grade cytokine release → smouldering malaise, low-grade fever | Think intra-abdominal (subphrenic, pelvic, hepatic), dental, cerebral; often FUO presentation |
| Endocarditis | Persistent bacteraemia → immune complex deposition, cytokine release → constitutional symptoms | New/changing murmur, splinter haemorrhages, Osler nodes, Janeway lesions, splenomegaly, embolic phenomena; positive blood cultures |
| Chronic infection (e.g. Lyme disease) [1] | Post-treatment immune dysregulation, ?persistent infection → chronic fatigue state | Travel history important; erythema migrans rash (early), arthritis, neuropathy (late) |
Why is TB a "pitfall"? Because elderly TB often presents atypically with ↑non-specific S/S as presenting symptoms, e.g. ↑weight loss, dyspnoea, malaise [10], and cryptic TB diagnosis is often delayed or missed → TB should be considered in ALL cases of pyrexia of unknown origin [10].
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Hypothyroidism | ↓T3/T4 → ↓basal metabolic rate → ↓ATP production in all cells → fatigue, cold intolerance, constipation, weight gain, cognitive slowing | TFTs: ↑TSH, ↓fT4. Common in women (Hashimoto's). Slow relaxing reflexes, dry skin, myxoedema |
| Diabetes mellitus [2] | Insulin resistance → impaired cellular glucose uptake → energy deficit despite hyperglycaemia; osmotic diuresis → dehydration; chronic inflammation | T2DM: usually asymptomatic at presentation with non-specific S/S, e.g. chronic fatigue and malaise [2]; polyuria/polydipsia; prevalence ~10% in HK |
| Adrenal insufficiency [4] | ↓Cortisol → inability to mount stress response, ↓gluconeogenesis → hypoglycaemia, ↓vascular tone → hypotension; ↓aldosterone → hypoNa, hyperK | Chronic adrenal insufficiency: chronic fatigue, malaise, weakness, (depression), anorexia and weight loss, hyperpigmentation (in primary only) [4]; diagnosed by short Synacthen test |
| Hypercalcaemia | ↑Ca²⁺ → ↓neuronal membrane excitability → fatigue, confusion, constipation; renal effects → dehydration | "Stones, bones, groans, moans, psychic overtones"; check corrected Ca |
| Hyponatraemia | ↓Na⁺ → ↓extracellular osmolarity → cellular swelling → cerebral oedema → lethargy, confusion, nausea | Check paired serum and urine osmolality; common in elderly (SIADH, diuretics) |
| Uraemia (CKD) | Accumulation of uraemic toxins → central neurotoxicity, nausea, anorexia; also ↓EPO → anaemia → tissue hypoxia | ↑Creatinine/urea, oedema, pruritus, nocturia; very common in HK (diabetic nephropathy) |
| Haemochromatosis [1] | Iron deposition in liver (hepatic dysfunction), pancreas (DM), heart (cardiomyopathy), joints (arthropathy) → multi-organ fatigue | Fatigue, arthralgia, hepatomegaly, skin pigmentation ("bronze diabetes"). ↑Ferritin, ↑transferrin saturation. HFE gene testing |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Anaemia [1] (any cause) | ↓Hb → ↓O₂ carrying capacity → tissue hypoxia → compensatory ↑HR/CO → eventual exhaustion | Pallor, tachycardia, exertional dyspnoea; iron studies, B12, folate, haemoglobin electrophoresis |
| Iron deficiency anaemia | As above + iron needed for mitochondrial enzymes → fatigue even before frank anaemia | Koilonychia, angular stomatitis, pica; microcytic hypochromic anaemia, ↓ferritin |
| B12/folate deficiency | Megaloblastic anaemia → tissue hypoxia; also ↓methylation of myelin → neuropathy → neurological fatigue | Glossitis, oral ulcers, angular stomatitis [11]; subacute combined degeneration in B12 def |
| Leukaemia (acute) [5] | BM failure → anaemia (fatigue), neutropenia (infections → sickness behaviour), thrombocytopenia | General fatigue in majority of patients, often precedes diagnosis for months [5]; pallor, bruising, infections, hepatosplenomegaly |
| Primary myelofibrosis [5] | BM fibrosis → pancytopenia → anaemia + infections; massive splenomegaly → abdominal discomfort, early satiety, further cytopenia | Severe fatigue as most common presenting symptom [5]; leucoerythroblastic blood film, tear-drop cells |
| Lymphoma | Cytokine production by tumour cells (IL-6, TNF-α) → constitutional symptoms; BM infiltration → cytopenias | B symptoms (fever, night sweats, weight loss > 10%), lymphadenopathy ± hepatosplenomegaly |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Cardiac arrhythmia [1] | ↓Effective CO due to loss of coordinated contraction or rate extremes → tissue hypoperfusion → fatigue | Palpitations, presyncope, irregular pulse; ECG, Holter monitor |
| Cardiomyopathy [1] | ↓Contractility → ↓CO → poor tissue perfusion → fatigue; neurohormonal activation (RAAS, SNS) → exhaustion | Exercise intolerance, dyspnoea; displaced apex beat, S3 gallop; Echo shows ↓EF |
| Incipient CCF [1] | As above — early HF presents with fatigue/malaise BEFORE classical oedema/dyspnoea because ↓CO initially compensated by neurohormonal activation (SNS/RAAS) but this compensation itself is metabolically costly | Exertional fatigue, subtle SOBOE; ↑BNP/NT-proBNP is sensitive early marker |
| Myocarditis | Viral-mediated myocardial inflammation → ↓contractility + systemic cytokine release → fatigue/malaise | Viral prodrome: recent flu-like illness with fever, arthralgia and malaise → then cardiac symptoms [12] |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| COPD | Chronic hypoxia + systemic inflammation (↑CRP, IL-6, TNF-α) → skeletal muscle wasting + central fatigue | Smoking history, chronic productive cough, progressive dyspnoea; spirometry: FEV₁/FVC < 0.7 |
| Sleep apnoea [1] | Repeated hypoxia-reoxygenation → oxidative stress → systemic inflammation; sleep fragmentation → ↓restorative sleep | Snoring, witnessed apnoeas, daytime somnolence, morning headache; Epworth Sleepiness Scale; polysomnography |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Coeliac disease [1] | Villous atrophy → malabsorption → iron/folate/B12 deficiency → anaemia → fatigue; also chronic inflammation | May have GI symptoms (diarrhoea, bloating) or be "silent" with only fatigue + anaemia; anti-tTG IgA |
| Food intolerance [1] | Chronic GI distress (bloating, diarrhoea) → disrupted nutrition, sleep, well-being | Lactose intolerance (80–90% East Asians), FODMAP sensitivity; temporal relationship with food |
| NAFLD / NASH [3] | Hepatic inflammation → cytokine release → fatigue; also associated metabolic syndrome (obesity, DM) → multiple contributors to fatigue | NASH: may present with fatigue, malaise and vague RUQ discomfort [3]; mild ↑AST/ALT |
| Chronic liver disease [3] | Progressive hepatic dysfunction → impaired detoxification, altered amino acid metabolism, ↑ammonia → central fatigue; also anaemia, coagulopathy | Stigmata of CLD (spider naevi, palmar erythema, gynaecomastia), jaundice, ascites |
| IBD | Chronic mucosal inflammation → cytokine-mediated fatigue; also → iron deficiency (blood loss), malabsorption, B12 deficiency (terminal ileum Crohn's) | Bloody diarrhoea (UC), abdominal pain, weight loss, extraintestinal manifestations |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| SLE | Immune complex deposition → complement activation → multi-organ inflammation → profound cytokine release → fatigue; also → anaemia (haemolytic or ACD), nephritis | Non-specific systemic upset early on, e.g. general malaise, arthralgia, myalgia, low-grade fever [13]; malar rash, photosensitivity; ANA, anti-dsDNA |
| MCTD [13] | Overlap of SLE/SSc/PM pathology → multi-system inflammation | Non-specific systemic upset early on → makes early dx difficult [13]; Raynaud, swollen digits; +ve anti-U1 RNP |
| RA | Chronic synovial inflammation → systemic cytokine release (TNF-α, IL-6) → fatigue, malaise; constitutional symptoms: fever, weight loss, anorexia, fatigue [14] | Symmetrical polyarthritis (MCP, PIP, wrist), morning stiffness > 30 min; +ve RF, ACPA |
| PMR | Large vessel/proximal joint inflammation → systemic IL-6 release → fatigue, malaise, anorexia | Elderly, bilateral proximal shoulder/hip stiffness ± girdle pain, ↑↑ESR/CRP; dramatic response to low-dose steroids |
| Sjogren's | Chronic lymphocytic infiltration of exocrine glands + systemic inflammation → fatigue in > 70% | Sicca syndrome (dry eyes, dry mouth), parotid enlargement, arthralgia |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Cancer [1] (any) | Tumour-derived cytokines (TNF-α = "cachectin", IL-6) → cancer-related fatigue and cachexia; paraneoplastic syndromes; anaemia of chronic disease | Weight loss, night sweats, new mass, lymphadenopathy; age/risk-factor appropriate |
| HCC | Especially relevant in HK (HBV-related) → hepatic dysfunction + tumour cytokine production | RUQ pain, weight loss, known HBV/cirrhosis; AFP, imaging |
| NPC | Southern Chinese predilection (EBV-related) | Neck mass (cervical LN metastasis), nasal symptoms, cranial nerve palsies |
| Lung cancer | Most common cancer death in HK; may present with non-specific malaise before respiratory symptoms | Cough, haemoptysis, weight loss, smoking history |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Malnutrition [15] | ↓Energy substrates → ↓ATP production; ↓protein → hypoalbuminaemia → oedema; ↓micronutrients → enzymatic dysfunction | General body habitus: muscle wasting (intercostals, thenar, temporal), depletion of subcutaneous fat, peripheral oedema, vitamin deficiency signs [15]; BMI < 18.5, weight loss ≥10% in 3 months |
| Vitamin D deficiency | Widespread in HK (indoor lifestyle, limited sun exposure); → proximal myopathy, bone pain, fatigue; also immunomodulatory effects | ↓25-OH vitamin D; proximal weakness, bone tenderness |
Always take a thorough drug history including self-medication, OTCs, alcohol, antianxiety, antipsychotics, antidepressants [1]:
| Drug Class | Mechanism of Fatigue/Malaise |
|---|---|
| Beta-blockers | ↓HR → ↓CO → fatigue; lipophilic agents (propranolol) cross BBB → central fatigue, depression |
| Statins | Mitochondrial dysfunction (↓CoQ10) → myalgia, myopathy → fatigue |
| Antihistamines (1st-gen) | Cross BBB → H1 blockade in CNS → sedation |
| Antihypertensives | ↓BP → ↓cerebral perfusion → lightheadedness, fatigue |
| Psychotropics | SSRIs (initial activation then potential fatigue), benzodiazepines (GABA potentiation → sedation), antipsychotics (D2/H1 blockade → sedation) |
| Chemotherapy | Directly cytotoxic → BM suppression (anaemia), mucosal inflammation, systemic cytokine release |
| Opioids | μ-receptor agonism in CNS → sedation, respiratory depression |
| Condition | Why It Causes Malaise | Key Distinguishing Features |
|---|---|---|
| Chronic fatigue syndrome (CFS) / ME | Immune dysregulation, autonomic dysfunction, mitochondrial dysfunction, neuroinflammation → post-exertional malaise is pathognomonic | Fatigue ≥6 months, not explained by other conditions, unrefreshing sleep, cognitive dysfunction, post-exertional malaise (worsening after minimal effort) — diagnosis of exclusion |
| Post-COVID condition | Viral persistence, autoimmunity, endothelial dysfunction, microthrombi → multisystem symptoms | Fatigue, brain fog, exertional intolerance ≥3 months after SARS-CoV-2; overlaps with CFS/ME |
| Fibromyalgia | Central sensitization → ↓pain threshold, ↑fatigue; overlapping neuroimmune dysfunction | Widespread pain (≥ 3 months), fatigue, unrefreshing sleep, cognitive disturbance; tender points |
This is crucial for narrowing the DDx at the bedside:
| Tempo | Key Differentials |
|---|---|
| Acute (days) | Viral infection (URTI, flu, COVID-19), acute medical illness (ACS, PE, DKA, adrenal crisis), drug side-effect, sepsis, electrolyte derangement |
| Subacute (weeks) | Post-viral, occult infection (TB, abscess, endocarditis), newly diagnosed DM/hypothyroidism, early depression, new medication, acute leukaemia |
| Chronic (months–years) | Depression, anxiety, CFS/ME, hypothyroidism, CKD, chronic liver disease, malignancy, autoimmune disease, sleep apnoea, lifestyle factors, anaemia |
When malaise accompanies neurological features, consider the nature-of-lesion framework [16]:
| Nature | Features | Example |
|---|---|---|
| Inflammatory | Fever (acute or chronic), generalized malaise, signs of infection or inflammation, e.g. LNs, skin rash, joint pain [16] | Encephalitis, meningitis, CNS vasculitis |
| Neoplastic / paraneoplastic | Insidious onset, progressive course, constitutional symptoms, e.g. loss of weight and appetite [16] | Brain tumour, paraneoplastic syndrome |
| Metabolic / toxic | Precipitating cause, e.g. drugs, exacerbation of previous systemic disorder, encephalopathy [16] | Hepatic encephalopathy, uraemic encephalopathy, Wernicke's |
| Degenerative | Older age group, gradual onset, progressive course [16] | Dementia (note: depression is most important mimic of dementia — "pseudodementia" [17]) |
When the history and examination do not clearly point to a diagnosis, Murtagh's key investigations [1] provide a systematic baseline screen:
| Investigation | What It Screens For |
|---|---|
| FBE (CBC) [1] | Anaemia, leukaemia/lymphoma (abnormal WBC, blasts), infection (↑WBC), thrombocytopenia |
| ESR/CRP [1] | Inflammation (infection, autoimmune, malignancy); very non-specific but useful as a screening tool |
| Blood sugar [1] | Diabetes mellitus |
| Serum electrolytes, calcium, magnesium [1] | Hyponatraemia, hypokalaemia, hypercalcaemia, hypomagnesaemia |
| Kidney function tests [1] | CKD, uraemia |
| Liver function tests [1] | Hepatitis, NAFLD, chronic liver disease, biliary obstruction |
| Iron studies [1] | Iron deficiency anaemia, haemochromatosis (↑ferritin, ↑transferrin saturation) |
| Faecal occult blood [1] | Occult GI bleeding (colorectal cancer, peptic ulcer, IBD) |
| Thyroid function tests [1] | Hypothyroidism, hyperthyroidism |
| CXR [1] | Lung cancer, TB, heart failure, sarcoidosis |
The Murtagh Baseline Panel is Your Safety Net
When a patient presents with chronic malaise and you have no clear clinical pointer after history and examination, this panel (FBE, ESR/CRP, blood sugar, electrolytes/Ca/Mg, RFT, LFTs, iron studies, FOB, TFTs, CXR) [1] will pick up the vast majority of serious organic causes. If this is all normal and you have screened for depression/anxiety, you can be reasonably confident that nothing dangerous is being missed — and you can then consider CFS/ME, functional disorders, or lifestyle factors.
Also from lecture slides — additional key examination points to guide DDx [1]:
- General inspection noting facial features, skin appearance and colour, hyperpigmentation, conjunctivae [1]
- Vital signs [1]
- Anthropometric measurements [1]
- Basic respiratory and cardiovascular [1]
- Abdominal examination with focus on masses and inguinal lymphadenopathy [1]
- Urinalysis [1]
And key history pointers [1]:
- General questions covering red flags, weight change, general discomfort, aches or pains, fever, unusual lumps or bumps (lymph nodes), bleeding, rashes or pruritus, sleep patterns including snoring, apnoea [1]
- Symptoms review especially gastrointestinal, cardiovascular and neurological [1]
- Drug history including self-medication, OTCs, alcohol, antianxiety, antipsychotics, antidepressants [1]
- Psychological: stresses, anxiety, depression, sexual problems [1]
- Social including relationships, abuse or bullying [1]
- Diet and exercise [1]
This is the most practical exam-oriented approach — when the patient has malaise plus one additional prominent feature, what should you think of?
| Malaise + ... | Top Differential |
|---|---|
| + Low mood / anhedonia | Depression (most common), hypothyroidism, adrenal insufficiency (chronic fatigue, malaise, weakness, depression) [4] |
| + Fever | Infection (acute viral, TB, abscess, endocarditis), lymphoma, autoimmune (SLE, adult-onset Still's), drug fever |
| + Weight loss | Malignancy, TB, hyperthyroidism, DM, Addison's, depression, CFS/ME |
| + Night sweats | TB, lymphoma, endocarditis, brucellosis, HIV |
| + Pallor | Anaemia (iron deficiency, B12/folate, haemolysis, leukaemia), CKD |
| + Joint pain | RA, SLE, MCTD [13], viral arthritis, reactive arthritis, PMR |
| + Lymphadenopathy | EBV [9] (lymphadenopathy 100%), lymphoma, HIV, TB, SLE |
| + Jaundice | Hepatitis (viral, autoimmune), haemolysis, biliary obstruction, acute liver failure |
| + Skin hyperpigmentation | Addison's, haemochromatosis |
| + Hepatosplenomegaly | EBV, leukaemia/lymphoma, cirrhosis with portal HTN, myelofibrosis |
| + Snoring / daytime sleepiness | Sleep apnoea [1] |
| + Post-exertional worsening | CFS/ME, cardiac failure |
| + Multiple somatic complaints | Somatic symptom disorder [8], masked depression |
High Yield Summary — DDx of General Malaise
- Most Common: Depression, anxiety, lifestyle factors, viral infection, sleep disorders [1]
- Must Not Miss: Cancer, leukaemia, HIV, TB, cardiac failure, anaemia, adrenal insufficiency, haemochromatosis [1]
- Often Missed: Masked depression, coeliac disease, food intolerance, chronic infection (TB, Lyme), hypothyroidism, CKD [1]
- HK-Specific: HBV (7–8%), TB (intermediate burden), thalassaemia, NPC, T2DM/metabolic syndrome, NAFLD
- Framework: Use Murtagh's probability → serious → pitfalls → rarities plus systems-based and tempo-based approaches
- Baseline Panel: FBE, ESR/CRP, blood sugar, electrolytes/Ca/Mg, RFT, LFTs, iron studies, FOB, TFTs, CXR [1]
- Always screen for depression — "masked depression" is the most commonly missed diagnosis in chronic malaise/fatigue
Active Recall - DDx of General Malaise
References
[1] Lecture slides: murtagh merge.pdf (p99, p101 — Tiredness/chronic fatigue) [2] Senior notes: Ryan Ho Endocrine.pdf (p80 — Workup for Newly Diagnosed DM) [3] Senior notes: Ryan Ho GI.pdf (p206 — Acute Liver Failure; p309 — NAFLD) [4] Senior notes: Ryan Ho Endocrine.pdf (p71 — Adrenal Insufficiency) [5] Senior notes: Ryan Ho Haemtology.pdf (p51 — Leukaemia; p78 — Primary Myelofibrosis) [6] Senior notes: Ryan Ho Psychiatry.pdf (p140 — Approach to Low Mood; p155 — Depressive Disorders) [7] Senior notes: Ryan Ho Psychiatry.pdf (p170, p173 — Anxiety Disorders, GAD) [8] Senior notes: Ryan Ho Psychiatry.pdf (p199, p203 — Somatoform Disorders) [9] Senior notes: Ryan Ho Respiratory.pdf (p49 — Acute Coryza; p53 — Infectious Mononucleosis) [10] Senior notes: Ryan Ho Respiratory.pdf (p81 — TB, Cryptic TB) [11] Senior notes: Ryan Ho Haemtology.pdf (p29 — B12/Folate Deficiency) [12] Senior notes: Ryan Ho Cardiology.pdf (p165 — Myocarditis) [13] Senior notes: Ryan Ho Rheumatology.pdf (p86 — MCTD) [14] Senior notes: Ryan Ho Rheumatology.pdf (p48 — RA systemic features) [15] Senior notes: Ryan Ho Fluids and Nutrition.pdf (p6 — Malnutrition) [16] Senior notes: Ryan Ho Neurology.pdf (p55 — What is the lesion?) [17] Senior notes: Ryan Ho Psychiatry.pdf (p88 — DDx of dementia including pseudodementia)
Diagnostic Approach to General Malaise
Let's be clear from first principles: general malaise is a symptom, not a disease. It has no diagnostic criteria of its own — the diagnostic task is to identify the underlying cause. This is fundamentally different from, say, diagnosing SLE (where you apply SLICC/ACR criteria) or depression (where you apply DSM-5 criteria). Instead, the approach to malaise is one of systematic exclusion: you use a structured clinical algorithm plus a baseline investigation panel to either (a) identify an organic cause, (b) identify a psychiatric cause, or (c) arrive at a diagnosis of exclusion (e.g. CFS/ME, functional disorder).
That said, several of the conditions that cause malaise do have formal diagnostic criteria — and you need to know the key ones. We will cover:
- The diagnostic algorithm — how to move from symptom to diagnosis
- The baseline investigation panel and interpretation of key findings
- Specific diagnostic criteria for the most important conditions presenting as malaise
The algorithm below integrates Murtagh's Key History, Key Examination, and Key Investigations [1] with a systematic clinical reasoning approach.
The 4-Step Approach
Step 1: Structured history (including psychological screen and drug history [1] — these are the most commonly skipped steps and catch the most commonly missed diagnoses: depression, anxiety, drug-related fatigue).
Step 2: Focused examination (hyperpigmentation → Addison's; conjunctival pallor → anaemia; abdominal masses → malignancy; inguinal lymphadenopathy → lymphoma, STI [1]).
Step 3: Baseline investigation panel (Murtagh's panel [1]).
Step 4: Either targeted workup if pointers exist, or formal psychiatric/sleep/lifestyle assessment if baseline is normal.
Baseline Investigation Panel: Detailed Interpretation
This is the key investigations panel from Murtagh's Diagnostic Strategies [1]. Each test is chosen to screen for a specific subset of serious causes. Let's go through every single one and explain why it is included and how to interpret the results.
Why: The single most information-dense screening test. It interrogates three cell lineages (red cells, white cells, platelets) simultaneously.
| Parameter | Abnormality | What It Suggests | Pathophysiological Basis |
|---|---|---|---|
| Haemoglobin | ↓ (anaemia) | Iron deficiency, B12/folate def, chronic disease, haemolysis, BM failure, thalassaemia | ↓Hb → ↓O₂ carrying capacity → tissue hypoxia → fatigue |
| MCV | ↓ (microcytic) | Iron deficiency, thalassaemia, chronic disease | ↓Iron → ↓haem synthesis → small RBCs with ↓Hb content |
| MCV | ↑ (macrocytic) | B12/folate deficiency, hypothyroidism, alcohol excess, MDS, liver disease, drugs (e.g. methotrexate) | Impaired DNA synthesis → delayed nuclear maturation → large precursors released |
| WBC | ↑ (leukocytosis) | Infection, inflammation, stress response, leukaemia | Marrow response to infection (neutrophilia) or uncontrolled proliferation (leukaemia) |
| WBC | ↓ (leukopenia) | BM failure, SLE, HIV, drugs, severe sepsis | ↓Production or ↑destruction/consumption |
| Differential | ↑Eosinophils | Allergy, parasites, Addison's, drug reaction, eosinophilic disorders | Loss of cortisol suppression of eosinophils (Addison's); Th2-driven production |
| Platelets | ↓ (thrombocytopenia) | BM failure, DIC, SLE, hypersplenism, ITP | ↓Production or ↑destruction/sequestration |
| Blood film | Blasts | Acute leukaemia | Immature cells released from failing marrow; >20% blasts in BM = diagnostic [5] |
| Blood film | Tear-drop cells | Myelofibrosis | RBCs deformed by squeezing through fibrosed marrow sinusoids [5] |
| Blood film | Leucoerythroblastic | Myelofibrosis, BM infiltration | Immature cells pushed out of replaced marrow into peripheral blood [5] |
Must-Know
If the FBE shows pancytopenia (↓Hb, ↓WBC, ↓platelets simultaneously), this narrows the DDx dramatically: think BM failure (aplastic anaemia, leukaemia, myelofibrosis, MDS), BM infiltration (metastatic cancer), hypersplenism, or severe B12/folate deficiency. Always request a blood film and consider bone marrow biopsy.
Why: Non-specific markers of systemic inflammation. They do not tell you what is inflamed, but they tell you something is.
| Marker | Mechanism | Interpretation |
|---|---|---|
| ESR (erythrocyte sedimentation rate) | ↑Fibrinogen and immunoglobulins → ↑rouleaux formation → RBCs sediment faster | Slow to rise, slow to fall. Useful for chronic conditions. Very ↑ ( > 100 mm/hr) → myeloma, GCA/PMR, malignancy, TB, endocarditis |
| CRP (C-reactive protein) | Acute phase reactant synthesized by hepatocytes in response to IL-6 | Rises within 6–8 hours, falls rapidly. Better for acute infections and monitoring treatment response. Very ↑ ( > 100 mg/L) → bacterial infection, major surgery, active vasculitis |
Pearl: A markedly elevated ESR ( > 100) with malaise in an elderly patient should make you think of GCA/PMR, myeloma, or metastatic cancer until proven otherwise. GCA diagnostic criteria require ESR > 50 mm/h [18].
Why: Screens for diabetes mellitus — an extremely common cause of chronic fatigue, especially in HK.
| Test | Cut-off | Interpretation |
|---|---|---|
| Fasting glucose | ≥ 7.0 mmol/L (two occasions) | Diagnostic of DM |
| Random glucose | ≥ 11.1 mmol/L + symptoms | Diagnostic of DM |
| HbA1c | ≥ 48 mmol/mol (6.5%) | Diagnostic of DM |
| HbA1c | 42–47 mmol/mol (6.0–6.4%) | Pre-diabetes → ↑risk progression |
T2DM is usually asymptomatic at diagnosis, with non-specific S/S e.g. chronic fatigue and malaise [2] — this is precisely why screening is so important.
Why: Electrolyte derangements are common, easily treatable causes of malaise, and can also indicate serious underlying disease.
| Abnormality | Key Causes | Symptoms/Signs |
|---|---|---|
| Hyponatraemia ( < 135 mmol/L) | SIADH (cancer, drugs, CNS disease), diuretics, adrenal insufficiency, heart failure, cirrhosis | Nausea, malaise, confusion, seizures (if severe/rapid). Why? → ↓ECF osmolality → water shifts into cells → cerebral oedema |
| Hypokalaemia ( < 3.5 mmol/L) | Diuretics, vomiting, diarrhoea, Conn's | Fatigue, weakness, arrhythmia. Why? → ↑resting membrane potential → muscle cell cannot depolarize normally |
| Hyperkalaemia ( > 5.0 mmol/L plasma) [19] | Renal failure, K-sparing diuretics, Addison's, DKA | Non-specific (malaise, vomiting, nausea), vague muscle weakness [19], arrhythmia. Why? → ↓resting membrane potential → prolonged depolarization → ↓excitability |
| Hypercalcaemia ( > 2.6 mmol/L corrected) | Primary hyperparathyroidism, malignancy (PTHrP, myeloma, bone mets) | Fatigue, confusion, constipation, polyuria, abdominal pain. "Stones, bones, groans, moans, psychic overtones" |
| Hypomagnesaemia ( < 0.7 mmol/L) | Alcohol, diuretics, PPI, diarrhoea | Fatigue, weakness, tremor, arrhythmia; often co-exists with hypokalaemia (Mg needed for Na/K-ATPase) |
Why: CKD is extremely common (especially in HK — high DM, HTN burden) and insidious. Uraemia causes fatigue well before the patient becomes symptomatic from fluid overload.
| Parameter | Abnormality | What It Indicates |
|---|---|---|
| Creatinine | ↑ | ↓GFR → CKD or AKI. Creatinine is freely filtered at glomerulus; as GFR falls, creatinine rises |
| Urea | ↑ | Can be raised by dehydration, GI bleed, high protein intake, or renal failure. Less specific than creatinine |
| eGFR | < 60 mL/min for > 3 months | CKD Stage 3+. Progressive accumulation of uraemic toxins → fatigue, nausea, anorexia |
Why: Screens for hepatitis, NAFLD, cirrhosis, biliary disease — all of which cause malaise.
| Pattern | Findings | Suggests |
|---|---|---|
| Hepatocellular | ↑↑ALT/AST, mildly ↑ALP/GGT | Hepatitis (viral, autoimmune, drug), NAFLD/NASH [3] |
| Cholestatic | ↑↑ALP/GGT, mildly ↑ALT/AST | Biliary obstruction, PBC, drug-induced cholestasis |
| Mixed | ↑ALT/AST + ↑ALP/GGT | Drug reaction, infiltrative disease |
| Synthetic failure | ↓Albumin, ↑PT/INR | Cirrhosis, ALF. ALF defined by INR ≥ 1.5 [3] |
De Ritis ratio (AST:ALT): > 2 suggests alcoholic liver disease; < 1 in NAFLD (but reversal occurs as fibrosis develops) [3].
Why: Iron deficiency is the most common nutritional deficiency worldwide and common cause of fatigue. Also screens for haemochromatosis.
| Parameter | Iron Deficiency | Anaemia of Chronic Disease | Haemochromatosis [1] |
|---|---|---|---|
| Serum iron | ↓ | ↓ | ↑ |
| Ferritin | ↓↓ ( < 15 μg/L diagnostic) | N or ↑ (acute phase reactant) | ↑↑ ( > 300 men, > 200 women) |
| Transferrin / TIBC | ↑ | ↓ or N | ↓ |
| Transferrin saturation | ↓ ( < 20%) | ↓ or N | ↑↑ ( > 45% — screening threshold) |
Ferritin Pitfall
Ferritin is both an iron storage protein AND an acute phase reactant. In a patient with chronic inflammation (e.g. RA, malignancy), ferritin can be normal or elevated even if the patient is truly iron-deficient. In this setting, a ferritin < 100 μg/L (rather than the usual < 15) suggests concurrent iron deficiency. If in doubt, check soluble transferrin receptor (↑ in true iron deficiency, normal in ACD).
Why: Screens for occult GI bleeding — a common cause of iron deficiency anaemia in patients presenting with fatigue, and importantly a red flag for colorectal cancer.
- Positive FOB → warrants further investigation with colonoscopy
- False positives: NSAIDs, red meat, aspirin, upper GI bleeding
- False negatives: intermittent bleeding, vitamin C (interferes with guaiac test)
- FIT (faecal immunochemical test): preferred over guaiac-based FOB — specific for human haemoglobin, not affected by diet
Why: Thyroid dysfunction is extremely common (especially hypothyroidism in women) and eminently treatable. Fatigue is the most common symptom of both hypo- and hyperthyroidism.
| Pattern | TSH | fT4 | Diagnosis |
|---|---|---|---|
| Primary hypothyroidism | ↑ | ↓ | Hashimoto's (anti-TPO+), post-thyroidectomy, post-RAI |
| Subclinical hypothyroidism | ↑ | Normal | Very common; may cause fatigue; treat if TSH > 10 or symptomatic |
| Hyperthyroidism | ↓ | ↑ | Graves' (TRAb+), toxic nodular goitre, thyroiditis |
| Central hypothyroidism | N or ↓ | ↓ | Pituitary/hypothalamic disease (rare); TSH alone would miss this |
Why: A single, cheap, widely available test that screens for multiple serious conditions simultaneously.
| Finding | What It Suggests |
|---|---|
| Hilar lymphadenopathy | Sarcoidosis, lymphoma, TB, lung cancer |
| Pulmonary infiltrates | TB (apical), pneumonia, ILD |
| Cardiomegaly | Heart failure, cardiomyopathy, pericardial effusion |
| Pleural effusion | Heart failure, malignancy, TB, PE |
| Mass lesion | Lung cancer, metastasis |
| Miliary pattern | Miliary TB (diffuse fine micronodular shadows ~1–2 mm) [10] |
Additional Targeted Investigations (When Baseline Is Abnormal or Red Flags Present)
These are ordered based on clinical pointers from Steps 1–3. Never shotgun all of these — let the history and baseline results guide you.
| Investigation | When to Order | Key Findings |
|---|---|---|
| Reticulocyte count | Anaemia identified on FBE | ↑ = appropriate marrow response (haemolysis, acute blood loss); ↓ = marrow failure/nutritional deficiency |
| Serum B12 and folate | Macrocytosis, neurological symptoms, glossitis | ↓B12: pernicious anaemia, veganism, terminal ileum disease; ↓folate: malnutrition, malabsorption, drugs |
| Haemoglobin electrophoresis | Microcytic anaemia in Chinese/SE Asian patient | Thalassaemia trait (very common in HK: α-thal ~3–4%, β-thal ~2–3%) |
| Blood film | Abnormal FBE, suspected haematological malignancy | Blasts (leukaemia), tear-drop cells (myelofibrosis), hypersegmented neutrophils (B12/folate def), rouleaux (myeloma) |
| Bone marrow aspirate/biopsy [5] | Suspected leukaemia, myelofibrosis, MDS, unexplained cytopenias | >20% blasts = acute leukaemia [5]; fibrosis (myelofibrosis); dysplastic changes (MDS). 5-step approach: Morphology, Cytochemistry, Immunophenotyping, Cytogenetics, Molecular genetics (MCICM) [5] |
| Serum protein electrophoresis | Unexplained ↑ESR, back pain, renal impairment, suspected myeloma | M-band/paraprotein → myeloma, Waldenström's |
| LDH, haptoglobin, DCT | Suspected haemolysis | ↑LDH, ↓haptoglobin, +ve DCT → autoimmune haemolytic anaemia |
| Investigation | When to Order | Key Findings |
|---|---|---|
| Blood cultures | Fever, suspected endocarditis, sepsis | Positive with specific organism → guide antibiotic therapy |
| HIV Ag/Ab combo test | Risk factors, unexplained lymphadenopathy, recurrent infections | 4th-gen test detects both p24 antigen and HIV-1/2 antibodies; window period ~2 weeks |
| HBsAg, anti-HCV | Abnormal LFTs, risk factors, HK patient | HBsAg+ → chronic HBV; anti-HCV+ → confirm with HCV RNA |
| Monospot / EBV serology | Young patient, pharyngitis, lymphadenopathy, atypical lymphocytes | Monospot (heterophile Ab) — rapid but ~25% false negative in first week; VCA IgM confirmatory [9] |
| Sputum AFB smear/culture | Chronic cough, night sweats, weight loss, abnormal CXR | AFB smear: rapid but ↓sensitivity (needs ≥10,000 organisms/mL); culture: gold standard (takes 2–8 weeks); TB-PCR: rapid molecular test [10] |
| IGRA / Mantoux test | Suspected latent TB, pre-immunosuppression screening | IGRA preferred (not affected by BCG vaccination; single visit). Does NOT distinguish latent from active TB |
| Investigation | When to Order | Key Findings |
|---|---|---|
| 9 am cortisol | Hyperpigmentation, postural hypotension, hypoNa + hyperK | < 100 nmol/L = adrenal insufficiency likely; > 500 nmol/L = essentially rules out; 100–500 = indeterminate → proceed to SST |
| Short Synacthen test (SST) [4] | Indeterminate 9am cortisol or high clinical suspicion of adrenal insufficiency | Procedure: 250 μg synacthen IV/IM bolus → serum cortisol at 0, 30, 60 min. Normal: peak cortisol > 550 nmol/L. Abnormal: peak < 400 nmol/L [4]. Does NOT distinguish 1° from 2° — need paired ACTH |
| Basal ACTH + cortisol [4] | To distinguish primary vs secondary adrenal insufficiency | Primary: ↑ACTH ↓cortisol. Secondary/tertiary: ↓ACTH ↓cortisol [4] |
| HbA1c | Screening for DM in chronic fatigue | ≥ 48 mmol/mol (6.5%) = DM; 42–47 = pre-diabetes |
| PTH + corrected Ca | Hypercalcaemia identified | ↑Ca + ↑PTH = primary hyperparathyroidism; ↑Ca + ↓PTH = malignancy (PTHrP), granulomatous disease (↑1,25-OH vit D) |
| Vitamin D | Proximal myopathy, bone pain, ↑risk groups | < 25 nmol/L = deficient; 25–50 = insufficient. Very common in HK (indoor lifestyle) |
| Investigation | When to Order | Key Findings |
|---|---|---|
| ANA | Joint pain, rash, multi-system features | +ve in SLE ( > 95%), MCTD, Sjögren's, scleroderma. Low specificity (~5% healthy pop also +ve) |
| Anti-dsDNA | ANA positive, suspected SLE | Highly specific for SLE; titre correlates with disease activity (especially lupus nephritis) |
| Anti-U1 RNP [13] | Suspected MCTD | Positive by definition in MCTD; powerful predictor for subsequent evolution into MCTD [13] |
| RF, ACPA | Suspected RA | RF: sensitive but not specific; ACPA: highly specific for RA (~95%) |
| Complement C3/C4 | Suspected SLE | ↓C3/C4 = complement consumption → active immune complex disease |
| ESR + CRP | Suspected PMR/GCA | GCA: ESR > 50 mm/h is diagnostic criterion [18]; PMR: typically ↑↑ESR/CRP with dramatic steroid response |
| Anti-tTG IgA | Suspected coeliac disease | Highly sensitive and specific (must check total IgA — if IgA-deficient, use anti-tTG IgG or anti-DGP) |
| Investigation | When to Order | Key Findings |
|---|---|---|
| ECG | Palpitations, exertional fatigue, syncope | AF, heart block, ST changes (ischaemia/myocarditis), long QT |
| BNP / NT-proBNP | Suspected heart failure | ↑ = ventricular stretch → heart failure. BNP > 100 pg/mL or NT-proBNP > 300 pg/mL highly suggestive. Very useful as rule-out test (high NPV) |
| Echocardiogram | Abnormal ECG, ↑BNP, new murmur | LV systolic/diastolic dysfunction, valvular disease, pericardial effusion, cardiomyopathy |
| Holter monitor | Intermittent palpitations, presyncope | Paroxysmal AF, intermittent heart block, VT — may explain episodes of fatigue |
| Investigation | When to Order | Key Findings |
|---|---|---|
| CT thorax-abdomen-pelvis | Weight loss, lymphadenopathy, abnormal CXR/bloods, suspected malignancy | Mass lesion, lymphadenopathy, hepatosplenomegaly, effusions |
| AFP | Suspected HCC (known HBV/cirrhosis in HK) | ↑ > 400 ng/mL + compatible imaging = diagnostic of HCC |
| LDH | Suspected lymphoma, germ cell tumour | Elevated → non-specific but supports diagnosis of lymphoproliferative disease |
| Tissue biopsy | Lymph node enlargement, mass lesion | Histological diagnosis = gold standard for any malignancy |
| Assessment | When to Use | Key Findings |
|---|---|---|
| PHQ-9 (Patient Health Questionnaire-9) | Screening for depression in all patients with chronic malaise | Score ≥ 10 = moderate depression; ≥ 15 = moderately severe; ≥ 20 = severe. Sensitivity ~88%, specificity ~88% |
| GAD-7 (Generalized Anxiety Disorder-7) | Screening for anxiety | Score ≥ 10 = moderate anxiety |
| Epworth Sleepiness Scale | Daytime somnolence, snoring | Score ≥ 10 = excessive daytime sleepiness → investigate for OSA |
| Polysomnography | Suspected OSA, narcolepsy, PLMD | AHI ≥ 5 with symptoms = OSA diagnosis |
Specific Diagnostic Criteria for Key Conditions Presenting as Malaise
Since depression is the single most common serious cause of chronic malaise that is frequently missed:
≥ 5 of the following symptoms present during the same 2-week period (at least one must be depressed mood OR loss of interest/pleasure):
| Criterion | Mnemonic (SIG E CAPS) |
|---|---|
| Sleep disturbance (insomnia or hypersomnia) | |
| Interest loss (anhedonia) | ★ Must have at least one of the two core symptoms |
| Guilt (excessive or inappropriate) | |
| Energy loss / fatigue | ← The symptom that brings them in with "malaise" |
| Concentration difficulty | |
| Appetite change (↑ or ↓) ± weight change | |
| Psychomotor agitation or retardation | |
| Suicidal ideation |
Plus: causes clinically significant distress or impairment; not attributable to substance or medical condition [6].
Diagnosis requires all of the following:
- Substantial reduction in ability to engage in pre-illness activities, lasting ≥ 6 months, with fatigue that is:
- Of new/definite onset (not lifelong)
- Not explained by excessive exertion
- Not substantially relieved by rest
- Post-exertional malaise (pathognomonic — worsening of symptoms after physical/cognitive/emotional effort)
- Unrefreshing sleep
- Plus at least ONE of: cognitive impairment ("brain fog") OR orthostatic intolerance
Key principle: CFS/ME is a diagnosis of exclusion. All organic and psychiatric causes must be systematically ruled out first. This is why the baseline panel [1] must be completed before considering this diagnosis.
| Criterion | Detail |
|---|---|
| A | ≥1 somatic symptom that is distressing or results in significant disruption of daily life [8] |
| B | Excessive thoughts, feelings, or behaviours related to somatic symptoms: (1) Disproportionate and persistent thoughts about seriousness; (2) Persistently high anxiety about health; (3) Excessive time and energy devoted to symptoms [8] |
| C | State of being symptomatic is persistent (typically > 6 months) [8] |
Note: Under DSM-5, medically unexplained symptoms alone do not qualify; nor does an underlying organic explanation disqualify the diagnosis [8].
Relevant when malaise + headache + elderly:
≥3 of the following 5 criteria [18]:
- Onset ≥ 50 years
- New headache
- Abnormalities of temporal artery on clinical examination
- ↑ESR ( > 50 mm/h)
- Abnormal findings on biopsy of temporal artery
Sensitivity 93.5%, specificity 91.2%.
Not formal "criteria" but the diagnostic pathway:
- Clinical suspicion: chronic fatigue, malaise, weakness, hyperpigmentation (primary), hypoNa + hyperK [4]
- Screening: 9 am cortisol
- Confirmation: Short Synacthen test: peak cortisol > 550 nmol/L = normal; < 400 nmol/L = abnormal [4]
- Differentiation: Paired ACTH: ↑ACTH = primary; ↓ACTH = secondary/tertiary [4]
- Aetiological workup (primary): 21-hydroxylase Ab (autoimmune), CT adrenals, VLCFA (adrenoleukodystrophy) [4]
This is a common and challenging clinical scenario. After completing the Murtagh baseline panel [1] and a thorough history/examination:
- Re-examine the history: Did you adequately screen for psychological factors (stress, anxiety, depression, sexual problems), social factors (relationships, abuse/bullying), diet and exercise [1]?
- Formally screen for depression (PHQ-9) and anxiety (GAD-7)
- Assess sleep: Epworth Sleepiness Scale; consider polysomnography if OSA suspected
- Consider medication review: Drug history including self-medication, OTCs, alcohol, antianxiety, antipsychotics, antidepressants [1]
- Safety-net: If symptoms are < 6 months, arrange follow-up in 4–6 weeks with repeat basic bloods — some conditions (e.g. early hypothyroidism, early leukaemia) may not be detectable on first testing
- If persistent > 6 months with all investigations normal: Consider CFS/ME, somatic symptom disorder, fibromyalgia — but only after genuine exhaustive exclusion
Diagnostic Pitfall
Insidious multisystem diseases must be ruled out before diagnosing a somatoform disorder — e.g. AIDS, SLE, MS, hyperparathyroidism, occult malignancy, chronic infections [8]. The consequence of missing an organic disease is far greater than the consequence of delayed psychiatric diagnosis. Investigations should be judicious — false-positive results may lead to unnecessary invasive investigations and risks [8].
High Yield Summary — Diagnosis of General Malaise
-
There are no diagnostic criteria for malaise itself — the task is to identify the cause via a structured algorithm.
-
4-Step Approach: Structured history → Focused examination → Baseline investigations → Targeted workup or psychiatric/sleep assessment.
-
Murtagh's Baseline Panel [1]: FBE, ESR/CRP, blood sugar, electrolytes/Ca/Mg, RFT, LFTs, iron studies, FOB, TFTs, CXR — this catches the vast majority of serious organic causes.
-
Key targeted investigations by system: Haematological (blood film, B12, BM biopsy), Infection (HIV, HBsAg, sputum AFB), Endocrine (9 am cortisol → SST, HbA1c, PTH), Autoimmune (ANA, anti-dsDNA, RF/ACPA, anti-tTG), Cardiac (ECG, BNP, Echo), Malignancy (CT TAP, biopsy).
-
Always formally screen for depression (PHQ-9) and anxiety (GAD-7) — these are the most common causes and the most commonly missed.
-
Diagnostic criteria to know: MDD (SIG E CAPS, ≥ 5/9 for ≥ 2 weeks), CFS/ME (fatigue > 6 months + PEM + unrefreshing sleep), Somatic symptom disorder (DSM-5 criteria A–C), GCA (ACR ≥ 3/5), Adrenal insufficiency (SST pathway).
-
If everything is normal: Re-evaluate history, screen psych/sleep, review drugs, safety-net, consider CFS/ME only after genuine exclusion.
Active Recall - Diagnosis of General Malaise
References
[1] Lecture slides: murtagh merge.pdf (p99, p101 — Tiredness/chronic fatigue: Key history, Key examination, Key investigations) [2] Senior notes: Ryan Ho Endocrine.pdf (p80 — Workup for Newly Diagnosed DM) [3] Senior notes: Ryan Ho GI.pdf (p206 — Acute Liver Failure; p309 — NAFLD) [4] Senior notes: Ryan Ho Endocrine.pdf (p71 — Adrenal Insufficiency: diagnosis and workup) [5] Senior notes: Ryan Ho Haemtology.pdf (p51 — Leukaemia: approach and diagnostic criteria) [6] Senior notes: Ryan Ho Psychiatry.pdf (p140, p143, p155 — Depressive Disorders: criteria and assessment) [8] Senior notes: Ryan Ho Psychiatry.pdf (p199, p200, p203 — Somatoform Disorders: criteria and DDx) [9] Senior notes: Ryan Ho Respiratory.pdf (p53 — Infectious Mononucleosis) [10] Senior notes: Ryan Ho Respiratory.pdf (p75, p81 — TB: diagnosis, cryptic TB) [13] Senior notes: Ryan Ho Rheumatology.pdf (p86 — MCTD: anti-U1 RNP) [18] Senior notes: Ryan Ho Neurology.pdf (p65 — Giant Cell Arteritis: diagnostic criteria) [19] Senior notes: Ryan Ho Chemical Path.pdf (p14 — Hyperkalaemia)
Management of General Malaise
Let's establish this from first principles: malaise is a symptom, not a disease. There is no "anti-malaise pill." The management of general malaise is fundamentally the management of the underlying cause. Once you identify and treat the cause, the malaise resolves. This means the diagnostic workup (covered in the previous section) and the management are inseparable — you cannot treat what you have not diagnosed.
That said, there are important general management principles that apply to every patient presenting with malaise regardless of cause, and there are specific management strategies for the most common and serious underlying conditions. We will cover both.
General Management Principles (All Patients)
These apply to every patient presenting with malaise, regardless of whether a specific cause has been identified. They come from Murtagh's Diagnostic Tips [1]:
"Believe the patient's symptoms" [1]. Malaise is subjective and invisible — patients often feel dismissed. Acknowledge their experience explicitly: "I understand you're feeling generally unwell and that this is affecting your life. Let's work together to find out why."
Why this matters: Therapeutic alliance is the foundation. If the patient does not feel believed, they will doctor-shop (common in somatization), not comply with treatment, and not return for follow-up. Moreover, "Ask the patient what they believe is the cause of their tiredness" [1] — this elicits their illness model and may reveal important clues (e.g. a patient who says "I think it's because I was diagnosed with cancer last year" tells you about cancer-related fatigue AND possible depression).
"Investigations are likely to be therapeutic and reassuring rather than diagnostic" [1]. In many cases where the baseline panel is normal, the very act of performing and explaining normal results provides reassurance that nothing serious has been missed.
- But: reassurance must be paired with a clear follow-up plan ("Your blood tests are normal, which is good news. I'd like to see you again in 4 weeks to check how you're doing") — not dismissive ("Your tests are fine, there's nothing wrong").
"Diet and exercise" [1] should be discussed in every consultation:
| Factor | Intervention | Why It Works |
|---|---|---|
| Physical activity | Structured graduated exercise programme (30 min moderate activity, 5 days/week) | Exercise ↑mitochondrial biogenesis, ↑endorphins, ↑serotonin, ↓systemic inflammation (↓IL-6, TNF-α over time), ↑sleep quality. Paradoxically, the most fatigued patients benefit the most |
| Sleep hygiene | Regular sleep-wake times, avoid screens 1 hr before bed, limit caffeine after noon, dark/cool bedroom | Consolidates circadian rhythm, ↑slow-wave sleep, ↓cortisol dysregulation |
| Diet | Balanced meals at regular intervals, adequate hydration, limit refined sugars and excessive alcohol | Prevents reactive hypoglycaemia, ensures micronutrient sufficiency, reduces alcohol-mediated sleep disruption |
| Stress management | Relaxation techniques, mindfulness, cognitive restructuring | ↓Chronic HPA axis activation → ↓cortisol → ↓neuroinflammation → ↓fatigue |
"Drug history including self-medication, OTCs, alcohol, antianxiety, antipsychotics, antidepressants" [1] — consider whether any current medication could be causing or worsening fatigue:
- Beta-blockers: Can you switch to a less lipophilic agent (e.g. atenolol instead of propranolol)?
- Statins: Is the patient symptomatic? Consider dose reduction, switch to alternate statin, or CoQ10 supplementation
- Sedating medications: Antihistamines, gabapentinoids, benzodiazepines, older antidepressants — can the dose be reduced or the drug changed?
- Alcohol: Even "moderate" drinking disrupts sleep architecture (↓REM) → advise reduction
- Schedule follow-up (typically 4–6 weeks)
- Advise patient to return sooner if new symptoms develop (weight loss, fever, lumps, bleeding, worsening fatigue)
- Repeat baseline investigations in 3–6 months if initial workup was negative but symptoms persist — some conditions (early leukaemia, evolving hypothyroidism, early malignancy) may only become apparent on repeat testing
Murtagh's Clinical Wisdom
"Be alert to depression including masked depression" [1]
"Be alert for the classic endocrine traps: hypothyroidism and Addison disease" [1]
"Tiredness in absence of red flags is unlikely to have an organic cause" [1]
"Do not overlook a sleep disorder" [1]
"Learn how to undertake a brief, good physical examination and practise effective time management" [1]
These aphorisms from Murtagh capture the essence of managing malaise in primary care. The most commonly missed diagnoses are depression, hypothyroidism, sleep apnoea, and Addison's — all of which are treatable.
Specific Management by Cause
Below we cover the management of the most important and common conditions presenting as malaise, organized by system. For each, we explain the treatment rationale from first principles, key drug indications/contraindications, and important HK-specific considerations.
A. Psychiatric Causes
Depression is the most common serious cause of chronic malaise. Management follows a stepped-care model:
| Severity (PHQ-9) | Management |
|---|---|
| Mild (5–9) | Active monitoring, lifestyle modification (exercise, sleep hygiene, stress management), guided self-help, brief psychological intervention |
| Moderate (10–19) | Antidepressant medication OR psychological therapy (CBT, interpersonal therapy); combination preferred if poor response |
| Severe (≥ 20) | Antidepressant + psychological therapy (combination recommended from outset); consider psychiatry referral; ECT if treatment-resistant or acutely suicidal |
First-line antidepressants: SSRIs (selective serotonin reuptake inhibitors)
| Drug | Mechanism | Key Points |
|---|---|---|
| Sertraline | Blocks SERT (serotonin transporter) → ↑synaptic 5-HT → downstream neuroplasticity and normalization of HPA axis | First choice in primary care: fewest drug interactions, safe in cardiac disease. Onset of action 2–4 weeks |
| Fluoxetine | As above, but long half-life (4–6 days) | Useful in adolescents; can cause activation early on; potent CYP2D6 inhibitor (drug interactions) |
| Escitalopram | S-enantiomer of citalopram, highly selective SERT blockade | Well tolerated, ↓drug interactions. QTc prolongation at high doses (max 20 mg) |
Contraindications/Cautions for SSRIs:
- Concurrent MAOIs (serotonin syndrome risk — wait ≥ 2 weeks washout)
- Hyponatraemia risk (especially in elderly — SSRIs → SIADH → ↓Na⁺)
- GI bleeding risk (↓platelet serotonin → ↓platelet aggregation; caution with NSAIDs/anticoagulants)
- QTc prolongation (citalopram, escitalopram at high doses)
Second-line options: SNRIs (venlafaxine, duloxetine), mirtazapine (useful if insomnia dominant — H1 blockade → sedation, also ↑appetite via 5-HT2C/H1 blockade)
Key concept: Antidepressants take 2–4 weeks to work because they need to induce neuroplastic changes (↑BDNF, dendritic remodelling) — not just ↑serotonin acutely. Always warn patients: "You may feel side effects before benefits. Stick with it for at least 4 weeks before we reassess."
| Treatment | Mechanism | Indications |
|---|---|---|
| CBT | Cognitive restructuring + behavioural exposure → breaks cycle of worry → ↓anxiety → ↓somatic symptoms (including fatigue) | First-line for mild-moderate GAD |
| SSRIs/SNRIs | As above for depression; also effective in anxiety (serotonin modulates amygdala reactivity) | First-line pharmacotherapy; sertraline, escitalopram, or venlafaxine |
| Pregabalin | Binds α2δ subunit of VGCC → ↓excitatory neurotransmitter release → ↓neuronal hyperexcitability | Second-line; licensed for GAD; useful if comorbid pain. Caution: sedation, dizziness, dependence potential |
| Benzodiazepines | GABA-A potentiation → ↑Cl⁻ influx → neuronal inhibition | Short-term ONLY ( < 2–4 weeks) for acute crises; NOT for long-term use (tolerance, dependence, cognitive impairment) |
Management principles are fundamentally different from standard medical management:
| Principle | Rationale |
|---|---|
| Single coordinating physician | Prevents doctor-shopping, contradictory advice, unnecessary investigations |
| Regular scheduled visits | Shifts dynamic from symptom-contingent to time-contingent → patient feels supported without needing to generate new symptoms for attention |
| Validate symptoms | "Believe the patient's symptoms" [1] — even if no organic cause found, the suffering is real |
| Limit investigations | Ix should be judicious — false-positive results may lead to unnecessary invasive investigations and risks [8]. Each normal test provides temporary reassurance but fuels the cycle if investigations are ordered reactively |
| CBT | Core therapy: identifies and modifies catastrophic health cognitions, reduces somatic hypervigilance, develops adaptive coping |
| Treat comorbid depression/anxiety | Comorbid anxiety/depression in 30–60% [8] — SSRIs can reduce both mood symptoms and somatic complaint severity |
| Gradual functional rehabilitation | Goal is improvement in functioning, not complete symptom resolution |
Management Error
A common mistake is to tell the patient "There's nothing wrong with you" or "It's all in your head." This invalidates their experience, destroys therapeutic alliance, and often drives them to another doctor. Instead: "Your tests have confirmed that there is no dangerous disease. I believe your symptoms are real — they arise from the way your nervous system is processing signals from your body, and we can work on this together."
B. Sleep Disorders
| Treatment | Mechanism | Indications |
|---|---|---|
| CPAP (Continuous Positive Airway Pressure) | Pneumatic splinting of the upper airway → prevents pharyngeal collapse during sleep → eliminates apnoeas/hypopnoeas → ↓sleep fragmentation → ↓daytime fatigue | First-line for moderate-severe OSA (AHI ≥ 15) or symptomatic mild OSA |
| Weight loss | ↓Parapharyngeal fat → ↓airway collapsibility | Recommended for ALL overweight/obese OSA patients. Weight reduction of 10–15% can ↓AHI by ~50% |
| Mandibular advancement device | Protrudes mandible → ↑retroglossal space → ↓airway obstruction | Alternative for mild-moderate OSA or CPAP-intolerant patients |
| Positional therapy | Lateral sleeping prevents gravitational tongue base collapse | For positional OSA (predominantly supine events) |
| Avoid alcohol/sedatives | These ↓pharyngeal muscle tone → ↑airway collapsibility | Universal advice |
| Treatment | Mechanism | Indications |
|---|---|---|
| CBT for insomnia (CBT-I) | Sleep restriction + stimulus control + cognitive restructuring + relaxation + sleep hygiene → breaks conditioned arousal cycle | First-line for chronic insomnia (superior to drugs long-term) |
| Sleep hygiene education | Addresses modifiable behavioural factors that perpetuate insomnia | Universal adjunct |
| Melatonin | Exogenous agonist of MT1/MT2 receptors → advances circadian phase → ↓sleep onset latency | Useful for circadian rhythm disorders, jet lag, elderly insomnia (sustained-release). Low side-effect profile |
| Z-drugs (zopiclone, zolpidem) | GABA-A agonist → sedation (more selective than benzodiazepines) | Short-term ( < 4 weeks) for acute insomnia; tolerance develops |
| Benzodiazepines | GABA-A potentiation | Last resort, short-term only; avoid in elderly (fall risk, cognitive impairment) |
C. Endocrine Causes
| Treatment | Mechanism | Key Points |
|---|---|---|
| Levothyroxine (T4) | Synthetic thyroxine → deiodinated peripherally to T3 (active hormone) → restores metabolic rate in all tissues | Start low, go slow in elderly/cardiac patients (e.g. 25 μg daily, ↑by 25 μg every 4–6 weeks); younger patients can start 50–100 μg. Take on empty stomach 30 min before food (otherwise absorption ↓ by ~20%). Monitor TSH at 6–8 weeks (T4 half-life ~7 days, so need ≥5 half-lives for steady state) |
| CI/Caution | Untreated adrenal insufficiency — must replace cortisol BEFORE starting T4 (otherwise T4 ↑metabolic rate → ↑cortisol demand → adrenal crisis) | Also caution in ischaemic heart disease (↑metabolic rate → ↑myocardial O₂ demand → angina) |
| Scenario | Treatment | Mechanism |
|---|---|---|
| Acute adrenal crisis [4] | Treat on clinical suspicion BEFORE investigations [4]: IV hydrocortisone 100 mg stat, then 50 mg q6–8h + aggressive IV saline (0.9% NaCl) + dextrose if hypoglycaemic | Hydrocortisone = synthetic cortisol → restores vascular tone (cortisol → ↑vascular sensitivity to catecholamines → ↑BP), restores gluconeogenesis → corrects hypoglycaemia, ↓immune dysregulation |
| Chronic adrenal insufficiency [4] | Oral hydrocortisone 15–25 mg/day in 2–3 divided doses (e.g. 10 mg AM, 5 mg noon, 5 mg PM — mimicking diurnal cortisol rhythm) + fludrocortisone 50–200 μg daily (if primary — for mineralocorticoid replacement) | Fludrocortisone ("fludro" = fluorinated → ↑mineralocorticoid activity) → Na⁺ retention, K⁺ excretion → restores volume and electrolytes. Not needed in secondary AI (aldosterone is regulated by RAAS, not ACTH, so preserved) |
| Sick-day rules | Double or triple hydrocortisone dose during intercurrent illness, surgery, trauma | Normally cortisol ↑↑ during stress; adrenal-insufficient patients cannot mount this response → risk of adrenal crisis without ↑dose |
| Medic-alert bracelet | Advise ALL patients with adrenal insufficiency to wear identification | In emergencies, paramedics must know to give IV hydrocortisone immediately |
Management of DM-associated fatigue centres on optimizing glycaemic control:
| Modality | Key Points |
|---|---|
| Lifestyle modification | First-line for all: diet (↓refined carbs, Mediterranean pattern), exercise (↑GLUT4 translocation → ↑glucose uptake), weight loss (↓insulin resistance) |
| Metformin | First-line pharmacotherapy for T2DM. Mechanism: ↓hepatic gluconeogenesis, ↑peripheral insulin sensitivity (via AMPK activation). CI: eGFR < 30 (lactic acidosis risk); caution eGFR 30–45 |
| SGLT2 inhibitors (empagliflozin, dapagliflozin) | Block glucose reabsorption in PCT → glycosuria → ↓glucose + ↓weight + cardiorenal benefits. Now first-line in T2DM with CVD or CKD. CI: recurrent genital infections, T1DM (euglycaemic DKA risk) |
| Insulin | Required in T1DM (always), late T2DM (β-cell failure), DKA, perioperative |
D. Haematological Causes
| Treatment | Mechanism | Key Points |
|---|---|---|
| Oral iron (ferrous sulphate 200 mg BD–TDS) | Provides elemental Fe²⁺ → absorbed in duodenum → incorporated into transferrin → delivered to erythroid marrow → haem synthesis | Side effects: nausea, constipation, black stools. Take on empty stomach with vitamin C (acid environment ↑Fe²⁺ absorption). Reticulocyte response in ~1 week, Hb ↑ ~10 g/L per 2 weeks. Continue 3 months after Hb normalizes to replenish stores |
| IV iron (ferric carboxymaltose) | IV bypasses GI absorption → rapid replenishment | Indications: intolerance of oral, malabsorption (coeliac, IBD), CKD, severe anaemia, need for rapid repletion. CI: active infection (iron feeds bacteria); anaphylaxis risk (small) |
| Treat the cause | Most important step — finding and fixing the source of blood loss/malabsorption | Pre-menopausal women: menorrhagia; post-menopausal/men: GI bleeding → colonoscopy + OGD mandatory to exclude malignancy |
| Treatment | Mechanism | Key Points |
|---|---|---|
| IM hydroxocobalamin | 1 mg IM every other day for 2 weeks (loading), then 1 mg every 3 months (maintenance) | Required for pernicious anaemia (intrinsic factor deficient → cannot absorb oral B12). IM bypasses GI absorption |
| Oral B12 (1–2 mg daily) | High-dose oral can achieve ~1% passive absorption even without IF | Suitable for dietary deficiency (vegans), mild deficiency. Not for pernicious anaemia or neurological involvement |
Critical: If B12 and folate are both deficient, replace B12 FIRST — giving folate alone can correct the anaemia but will NOT halt neurological progression (subacute combined degeneration) and may even worsen it (folate drives cell division using B12-dependent methionine synthase → ↑B12 consumption → ↑neurological deficit).
Approach: 5 steps to diagnosis of haematological malignancy (MCICM) [5]:
- Morphology: peripheral blood smear, BM aspirate and trephine
- Cytochemistry: MPO/Sudan black B for myeloid
- Immunophenotyping: flow cytometry
- Cytogenetics: karyotyping, FISH
- Molecular genetics: PCR, sequencing
Management: Urgent referral to haematology. Treatment depends on subtype:
- AML: Induction chemotherapy (daunorubicin + cytarabine "7+3"), then consolidation ± allogeneic stem cell transplant
- ALL: Multi-agent chemotherapy (vincristine, dexamethasone, L-asparaginase), CNS prophylaxis, ± transplant
- Myelofibrosis [5]: JAK2 inhibitors (ruxolitinib) for symptomatic splenomegaly and constitutional symptoms; transplant for eligible patients
E. Infection-Related Causes
| Scenario | Management |
|---|---|
| Acute viral URTI | Symptomatic relief: rest, adequate hydration, paracetamol for fever/myalgia, nasal decongestants. Antibiotics NOT indicated. Self-limiting ~7–10 days [9] |
| Post-viral fatigue | Reassurance that post-viral fatigue is common and usually self-limiting (weeks to months); graded return to activity; adequate sleep; consider psychology referral if prolonged |
| Infectious mononucleosis (EBV) [9] | Supportive: rest, analgesia, hydration. Avoid contact sports for ≥ 3 weeks (splenic rupture risk — splenomegaly in 50–60%). Fatigue may persist for up to 6 months in 10% [9] — reassure. Steroids only if airway obstruction from tonsillar hypertrophy |
| Phase | Treatment | Duration |
|---|---|---|
| Intensive | RIPE: Rifampicin + Isoniazid + Pyrazinamide + Ethambutol | 2 months |
| Continuation | Rifampicin + Isoniazid | 4 months |
| Drug | Mechanism | Key Side Effects |
|---|---|---|
| Rifampicin | "Rif" = rifamycin family → inhibits bacterial DNA-dependent RNA polymerase → ↓mRNA synthesis | Hepatotoxicity, orange discolouration of secretions, CYP450 inducer (↓effect of OCP, warfarin, antiretrovirals) |
| Isoniazid | Prodrug activated by KatG → inhibits mycolic acid synthesis (cell wall component unique to mycobacteria) | Peripheral neuropathy (↓pyridoxine/B6 → always co-prescribe B6), hepatotoxicity |
| Pyrazinamide | Converted to pyrazinoic acid in acidic environment (macrophage phagolysosome) → disrupts membrane function | Hepatotoxicity, hyperuricaemia (↓renal urate excretion → gout flare) |
| Ethambutol | "Etham" → inhibits arabinosyl transferase → ↓arabinogalactan synthesis (cell wall) | Optic neuritis (↓visual acuity, colour vision → always check baseline acuity before starting) |
Cryptic TB in elderly: anti-TB treatment even in absence of definite evidence can be life-saving [10] — the 80% mortality without treatment justifies empirical therapy in high-suspicion cases.
- Antiretroviral therapy (ART): Start immediately upon diagnosis regardless of CD4 count (current WHO/DHHS guidelines 2025–2026)
- ART reduces viral load → ↓chronic immune activation → resolution of fatigue/malaise
- Typically: 2 NRTIs + 1 INSTI (e.g. tenofovir alafenamide + emtricitabine + bictegravir — single-tablet regimen)
Relevant in HK (HBV carrier rate ~7–8%):
| Indication for Treatment | Treatment | Mechanism |
|---|---|---|
| Active CHB (↑ALT, HBV DNA > 2000 IU/mL, ± significant fibrosis) | Entecavir or Tenofovir (oral NUC) | Nucleos(t)ide analogues → inhibit HBV DNA polymerase/reverse transcriptase → ↓viral replication → ↓hepatic inflammation → ↓fatigue |
| Selected patients | Pegylated IFN-α (finite course 48 weeks) | Immunomodulation + direct antiviral → chance of HBsAg seroconversion. CI: decompensated cirrhosis, autoimmune disease, psychiatric illness |
F. Cardiac Causes
| Drug Class | Mechanism | Why It Helps Malaise | Key CI |
|---|---|---|---|
| ACEi/ARB (ramipril, losartan) | ↓Angiotensin II → ↓afterload + ↓aldosterone → ↓Na/H₂O retention → ↓cardiac workload | ↓Neurohormonal overdrive → ↓chronic fatigue | Bilateral renal artery stenosis, pregnancy, angioedema (ACEi) |
| Beta-blocker (bisoprolol, carvedilol) | ↓HR → ↑diastolic filling time → ↑CO; ↓sympathetic overdrive → ↓myocardial O₂ demand | Paradox: beta-blockers can cause fatigue initially but ↓mortality and ↑exercise tolerance long-term (reverse remodelling) | Acute decompensation, severe bradycardia, asthma (non-selective) |
| MRA (spironolactone, eplerenone) | ↓Aldosterone → ↓fibrosis, ↓Na/H₂O retention | ↓Congestion and ↓cardiac remodelling → ↑functional capacity | Hyperkalaemia (K > 5.0), severe renal impairment |
| SGLT2i (dapagliflozin, empagliflozin) | Multiple mechanisms: natriuresis, ↓preload, ↓inflammation, ↑ketone body utilization by myocardium | Now standard of care in HFrEF AND HFpEF — ↓hospitalizations, ↑symptoms | Recurrent genital infections; caution in very low BP |
| Diuretics (furosemide) | Loop diuretic → ↓fluid overload | Symptomatic relief of congestion → ↓dyspnoea → ↑functional capacity. Does not improve mortality |
- Rate control for AF: Beta-blocker or rate-limiting CCB (diltiazem, verapamil) or digoxin → ↓ventricular rate → ↑diastolic filling → ↑effective CO → ↓fatigue
- Rhythm control: Consider if symptomatic despite rate control — flecainide, amiodarone, or catheter ablation
- Bradycardia/heart block: Pacemaker if symptomatic (fatigue, presyncope, syncope)
G. Autoimmune / Connective Tissue Diseases
| Treatment | Mechanism | Key Points |
|---|---|---|
| Hydroxychloroquine | Immunomodulator: ↓TLR signalling, ↓antigen presentation, ↓cytokine production | First-line for SLE (reduces flares, fatigue, skin disease); recommended for ALL SLE patients unless CI. CI: retinal toxicity (annual eye screening required), G6PD deficiency |
| Corticosteroids | ↓NF-κB → global immunosuppression → rapid ↓inflammation → rapid symptom relief | Used for flares (high dose, then taper). Long-term side effects: Cushing's, osteoporosis, DM, infections → always steroid-sparing strategy |
| DMARDs (methotrexate, azathioprine, mycophenolate) | Various: MTX inhibits DHFR → ↓purine synthesis → ↓lymphocyte proliferation; AZA → purine analogue; MMF → ↓inosine monophosphate dehydrogenase | Steroid-sparing agents; slow onset (weeks-months). MTX CI: pregnancy (teratogenic), significant renal/hepatic impairment. Monitor FBE, LFTs |
| Biologics (rituximab, belimumab) | Rituximab: anti-CD20 → B-cell depletion; Belimumab: anti-BLyS → ↓B-cell survival | For refractory disease. Pre-screen for HBV (rituximab → HBV reactivation risk) |
- Prednisolone 15 mg daily: Dramatic response (within 24–72 hours) is essentially diagnostic. Failure to respond should prompt reconsideration of diagnosis
- Gradual taper over 12–18 months guided by symptoms + ESR/CRP
- Always check for concurrent GCA symptoms (headache, jaw claudication, visual symptoms) → if present, escalate to 40–60 mg
Cancer-related fatigue (CRF) is multifactorial and requires multimodal management:
| Intervention | Mechanism |
|---|---|
| Treat the cancer | ↓Tumour burden → ↓cytokine production → ↓sickness behaviour |
| Treat anaemia | ↑Hb → ↑O₂ delivery. Transfusion if Hb < 70 g/L (or symptomatic at higher levels); EPO for chemotherapy-induced anaemia |
| Exercise | Even in cancer patients, structured exercise programmes ↓fatigue (strongest evidence base of any CRF intervention) |
| Psychosocial support | CBT, mindfulness-based stress reduction → ↓distress → ↓fatigue |
| Pharmacotherapy | Methylphenidate/dexamfetamine (psychostimulants) — limited evidence, sometimes used in palliative care; corticosteroids (short-term benefit for terminally ill) |
This is the management when all organic and psychiatric causes have been excluded and fatigue persists > 6 months:
| Intervention | Rationale | Notes |
|---|---|---|
| Patient education | Understanding the condition ↓helplessness → ↑self-efficacy | Explain that CFS/ME is a real, recognized condition with neurobiological underpinnings — not laziness or "imaginary" |
| Pacing | Activity management to stay within "energy envelope" → ↓post-exertional malaise | Patient learns to recognize limits and alternate activity/rest. Avoid boom-bust cycle |
| Graded exercise therapy (GET) | Very gradual ↑physical activity from a very low baseline → ↑deconditioning tolerance | Controversial — must be patient-led, not rigid. NICE 2021 moved away from GET as structured programme but supports individually tailored physical activity increases |
| CBT | Addresses unhelpful illness cognitions (catastrophizing, fear-avoidance), ↑adaptive coping | Does NOT imply illness is psychological; targets coping strategies and functional outcomes |
| Sleep management | Sleep hygiene, melatonin, treat comorbid sleep disorders | Unrefreshing sleep is a core feature — improving sleep quality ↑overall function |
| Symptom management | Paracetamol/NSAIDs for pain; low-dose amitriptyline for sleep + pain (H1/muscarinic blockade → sedation; ↓reuptake NE/5-HT → pain modulation); gabapentin for neuropathic-type pain | Avoid opioids (tolerance, dependence, cognitive effects → worsen fatigue) |
| Cause | Key Treatment | Critical Don't-Miss Point |
|---|---|---|
| Depression | SSRI + CBT | Screen with PHQ-9; warn about 2–4 week onset lag |
| Anxiety | SSRI/SNRI + CBT | Benzodiazepines SHORT-TERM only |
| Somatic symptom disorder | Single physician, scheduled visits, CBT, limit Ix [8] | Validate, do not dismiss |
| OSA | CPAP + weight loss | Ask about snoring in EVERY fatigued patient [1] |
| Hypothyroidism | Levothyroxine | Replace cortisol first if adrenal insufficiency coexists |
| Adrenal insufficiency [4] | Hydrocortisone ± fludrocortisone | Acute crisis: treat BEFORE Ix [4]; sick-day rules |
| DM | Lifestyle + metformin ± SGLT2i | Fatigue improves with glycaemic optimization |
| Iron deficiency | Oral/IV iron + investigate cause | Men/post-menopausal women → exclude GI malignancy |
| B12 deficiency | IM hydroxocobalamin | Replace B12 before folate |
| Leukaemia [5] | Urgent haematology referral | MCICM 5-step diagnostic workup [5] |
| Viral infection | Supportive, symptomatic | Antibiotics NOT indicated for viral URTI [9] |
| TB [10] | RIPE regimen 2+4 months | Co-prescribe pyridoxine with isoniazid |
| HIV | ART regardless of CD4 | Single-tablet regimens improve compliance |
| CHB | Entecavir/tenofovir if indicated | HK high prevalence — always screen |
| Heart failure | ACEi + BB + MRA + SGLT2i + diuretics | Quadruple therapy is now standard for HFrEF |
| SLE/CTD | HCQ for all SLE + steroids + DMARDs | Annual retinal screening for HCQ |
| PMR | Prednisolone 15 mg | Dramatic response expected — if not, reconsider dx |
| CFS/ME | Pacing, CBT, sleep management, graded activity | Diagnosis of exclusion only |
| Malignancy | Treat cancer + exercise + anaemia management | Referral to oncology |
High Yield Summary — Management of General Malaise
-
Core principle: Treat the cause, not the symptom. There is no "anti-malaise" drug.
-
General measures for ALL patients: Validate symptoms ("believe the patient") [1], lifestyle advice (diet and exercise) [1], medication review, sleep assessment ("do not overlook a sleep disorder" [1]), safety-netting.
-
"Investigations are likely to be therapeutic and reassuring rather than diagnostic" [1] — a normal baseline workup itself is part of the management.
-
"Be alert to depression including masked depression" [1] — screen every patient with PHQ-9. SSRIs are first-line pharmacotherapy.
-
"Be alert for the classic endocrine traps: hypothyroidism and Addison disease" [1] — levothyroxine for hypothyroidism (start low, go slow); hydrocortisone ± fludrocortisone for adrenal insufficiency (treat acute crisis before investigations [4]).
-
"Tiredness in absence of red flags is unlikely to have an organic cause" [1] — but still do the baseline panel, review in 4–6 weeks, and repeat tests if symptoms persist.
-
Iron deficiency: Oral iron + identify and treat the source of loss. Men/postmenopausal women → investigate for GI malignancy.
-
TB in HK: RIPE 2+4 months. Empirical anti-TB treatment can be life-saving in cryptic TB [10].
-
CFS/ME: Diagnosis of exclusion. Pacing, CBT, sleep management, gradually increasing activity. No specific drug treatment.
-
Somatic symptom disorder: Single physician, scheduled visits, limit investigations (false positives cause harm) [8], CBT, treat comorbid depression/anxiety.
Active Recall - Management of General Malaise
References
[1] Lecture slides: murtagh merge.pdf (p99, p101, p102 — Tiredness/chronic fatigue: Key history, Key examination, Key investigations, Diagnostic tips) [2] Senior notes: Ryan Ho Endocrine.pdf (p80 — Workup for Newly Diagnosed DM) [4] Senior notes: Ryan Ho Endocrine.pdf (p71 — Adrenal Insufficiency: management) [5] Senior notes: Ryan Ho Haemtology.pdf (p51 — Leukaemia: MCICM approach) [8] Senior notes: Ryan Ho Psychiatry.pdf (p199, p200, p202, p203 — Somatoform Disorders: management and criteria) [9] Senior notes: Ryan Ho Respiratory.pdf (p49, p53 — Acute Coryza, Infectious Mononucleosis) [10] Senior notes: Ryan Ho Respiratory.pdf (p75, p81 — TB: treatment, Cryptic TB)
Complications of General Malaise
Because general malaise is a symptom rather than a disease, we cannot discuss "complications of malaise" in the traditional sense — the way you would for, say, complications of diabetes or post-operative complications. Instead, we must think about this in three interrelated ways:
- Complications of the underlying cause — the diseases producing malaise each carry their own complication profiles
- Complications of delayed or missed diagnosis — when malaise is dismissed or inadequately investigated, serious underlying pathology progresses
- Consequences of chronic unexplained malaise itself — the functional, psychological, and socioeconomic impact when malaise persists without clear diagnosis
All three are clinically important and examinable. Let's cover them systematically.
Each condition in the differential produces malaise as an early/constitutional symptom. If the underlying condition is not identified and treated, it progresses to its own disease-specific complications. The table below maps the most common/important causes of malaise to the critical complications that develop if missed.
| Underlying Cause | Critical Complications if Untreated | Pathophysiology of Progression |
|---|---|---|
| Depression | Suicide (most feared), self-harm, substance abuse, social withdrawal, functional disability, cardiovascular morbidity (RR 1.2–4.0×) [6] | Untreated depression → progressive neurobiological deterioration (↓hippocampal volume, ↑HPA axis dysregulation) → ↑severity, ↑suicidality. Also → behavioural risk factors (↓adherence to medical treatment, ↓activity, ↑alcohol) → ↑medical morbidity |
| Hypothyroidism | Myxoedema coma (rare but life-threatening): hypothermia, ↓GCS, bradycardia, hypoventilation, hyponatraemia | Progressive ↓T3/T4 → ↓metabolic rate across all organs → cardiac failure, respiratory failure, hypothermia. Precipitated by cold exposure, infection, sedatives |
| Adrenal insufficiency [4] | Acute adrenal crisis: circulatory shock out of proportion to illness, severe hypotension, unexplained hypoglycaemia [4] | Chronic fatigue and malaise precede the crisis [4]. Intercurrent infection/surgery → ↑cortisol demand that cannot be met → vascular collapse (cortisol required for vascular tone → permissive effect on catecholamines), hypoglycaemia (↓gluconeogenesis), electrolyte crisis (↓aldosterone → hyperK, hypoNa) |
| Diabetes mellitus [2] | Microvascular (retinopathy, nephropathy, neuropathy), macrovascular (MI, stroke, PVD), DKA, HHS | T2DM often presents as chronic fatigue/malaise [2] — if undiagnosed, years of hyperglycaemia → glycation of proteins → endothelial dysfunction → organ damage |
| Iron deficiency anaemia | High-output cardiac failure (if severe/chronic), impaired cognitive development (children), adverse pregnancy outcomes | Chronic ↓Hb → compensatory ↑CO → ventricular dilatation → eventual HF. More critically: missed IDA in older adults may represent occult colorectal cancer → metastatic disease if diagnosis delayed |
| B12 deficiency | Subacute combined degeneration of the cord (irreversible if treatment delayed), megaloblastic anaemia, peripheral neuropathy | B12 required for methylation of myelin proteins → ↓B12 → demyelination of dorsal columns (↓proprioception) and lateral columns (↓motor) → paraparesis + sensory ataxia. Neurological damage can occur in the absence of haematological changes and may be irreversible [11] |
| Acute leukaemia [5] | DIC (especially APML — severe bleeding suggestive of APML → look for lab evidence of DIC [5]), tumour lysis syndrome, neutropenic sepsis, intracranial haemorrhage | General fatigue often precedes diagnosis for months [5] → if missed, rapidly fatal from BM failure complications (infection, haemorrhage) or metabolic catastrophe |
| Primary myelofibrosis [5] | Massive splenomegaly (splenic infarction, early satiety, cachexia), transformation to AML (10–20%), portal hypertension | Severe fatigue is the most common presenting symptom [5] → progressive BM fibrosis → pancytopenia → infections, bleeding, AML transformation |
| TB [10] | Miliary dissemination, TB meningitis, multi-organ failure, transmission to contacts, drug resistance if partially treated | Cryptic TB: diagnosis often delayed or missed → very poor outcome (80% mortality) [10]. Smouldering infection → haematogenous dissemination → miliary TB → multi-organ involvement |
| HIV/AIDS | Opportunistic infections (PCP, CMV, toxoplasmosis, cryptococcal meningitis), AIDS-defining cancers (Kaposi's, lymphoma), progressive immune failure | Untreated → CD4 decline → susceptibility to opportunistic pathogens → severe morbidity/mortality. Early ART prevents nearly all of these |
| Chronic hepatitis B | Cirrhosis, hepatocellular carcinoma, liver failure | HK carrier rate 7–8%. Chronic inflammation → stellate cell activation → fibrosis → cirrhosis (over decades). HBV DNA integration → HCC (even without cirrhosis, but much higher risk with) |
| Heart failure | Acute pulmonary oedema, cardiogenic shock, arrhythmia (AF, VT/VF), sudden cardiac death, renal failure (cardiorenal syndrome) | Incipient CCF [1] initially presents with fatigue/malaise → if missed, progressive ventricular remodelling → decompensation → pulmonary oedema, ↓CO → shock |
| Cancer [1] | Metastatic disease, organ failure, cachexia, paraneoplastic syndromes, death | Malaise may be the earliest constitutional symptom → delayed investigation → tumour progresses from potentially curable to incurable |
| OSA [1] | Hypertension (resistant), cardiovascular events (MI, stroke, arrhythmia), metabolic syndrome, road traffic accidents (daytime somnolence), pulmonary hypertension | Chronic intermittent hypoxia → endothelial dysfunction + sympathetic activation → HTN, atherosclerosis. Sleep fragmentation → microsleep episodes → RTA risk ↑ 2–3× |
| Giant cell arteritis [18] | Permanent blindness (arteritic AION), aortic aneurysm/dissection, stroke | Systemic S/S: fever, anorexia, malaise, PMR [18] → malaise may be the presenting symptom before headache/visual symptoms → if steroids not started urgently → irreversible visual loss in hours |
The Danger of Dismissing Malaise
The single most important concept: malaise is a "check engine light" — it may represent something trivial (viral URTI, poor sleep) or something life-threatening (leukaemia, adrenal insufficiency, occult cancer). The complications arise NOT from the malaise itself but from failure to diagnose the underlying cause in time. Every serious condition listed above has an early phase where malaise is the dominant or sole symptom, and a late phase where irreversible damage has occurred. The clinician's job is to catch diseases in the early phase.
2. Complications of Delayed or Missed Diagnosis
This deserves separate emphasis because it is the most practically important and most examinable aspect.
"Be alert to depression including masked depression" [1]. Depression is the most commonly missed serious cause of chronic fatigue. If missed:
- Untreated depression has a lifetime suicide risk of ~15% in severe cases
- Progressive functional disability → job loss, relationship breakdown, social isolation
- Development of treatment resistance (the longer depression goes untreated, the harder it is to treat — neuroplastic changes become entrenched)
"Be alert for the classic endocrine traps: hypothyroidism and Addison disease" [1]. If hypothyroidism is missed in an elderly patient presenting with "tiredness," they are at risk of:
- Progressive cognitive decline (misdiagnosed as dementia)
- Myxoedema coma if intercurrent illness supervenes (mortality 20–50% even with treatment)
- Unnecessary psychiatric treatment (misdiagnosed as depression)
Chronic adrenal insufficiency: non-specific, often mis-diagnosed as depression [4]. This is a classic diagnostic pitfall:
- Chronic fatigue, malaise, weakness, depression [4] — all overlap with common psychiatric diagnoses
- Patient may function at low level for months/years until a physiological stressor (infection, surgery, trauma) precipitates acute adrenal crisis: circulatory shock, hypoglycaemia [4]
- Adrenal crisis has mortality of 6–8% even in known Addison's patients and is nearly always fatal if undiagnosed
Cancer [1] often presents initially with non-specific constitutional symptoms (malaise, fatigue, anorexia, weight loss). If the clinician does not investigate:
- A potentially curable Stage I/II cancer progresses to incurable Stage IV
- This is particularly relevant for:
- Colorectal cancer: IDA in an older adult with fatigue → failure to perform colonoscopy → diagnosis at advanced stage
- Haematological malignancy: fatigue + mild cytopenias dismissed as "anaemia of chronic disease" → blastic crisis
- HCC: fatigue in a known HBV carrier not enrolled in surveillance → presentation with advanced/ruptured HCC
"Do not overlook a sleep disorder" [1]. OSA causes excessive daytime somnolence → 2–3× increased risk of motor vehicle accidents. Also → resistant hypertension, ↑cardiovascular events. A simple Epworth Sleepiness Scale screening can prevent these complications.
3. Consequences of Chronic Unexplained Malaise
When malaise persists for months despite adequate investigation — whether ultimately diagnosed as CFS/ME, fibromyalgia, somatic symptom disorder, or truly idiopathic — the malaise itself produces secondary complications:
| Domain | Impact | Mechanism |
|---|---|---|
| Occupational | Reduced work capacity, absenteeism, job loss, financial hardship | Fatigue → ↓productivity → inability to meet work demands → unemployment (CFS/ME patients have ~50% unemployment rate) |
| Physical deconditioning | Muscle wasting, ↓aerobic capacity, ↓exercise tolerance | Fatigue → ↓activity → ↓mitochondrial density, ↓muscle mass, ↓cardiovascular fitness → worsening fatigue (vicious cycle) |
| ADL impairment | Difficulty with basic self-care, cooking, shopping, socializing | Energy envelope so reduced that even routine activities trigger post-exertional malaise (in CFS/ME) |
| Complication | Mechanism |
|---|---|
| Secondary depression | Chronic illness → loss of role, social isolation, hopelessness → depressive episode (50–75% of CFS/ME patients develop comorbid depression) |
| Anxiety | Uncertainty about diagnosis → health anxiety; fear of worsening → avoidance behaviour |
| Loss of self-identity | Inability to fulfil previous roles (worker, parent, spouse) → identity crisis, grief |
| Iatrogenic harm | Excessive investigation (radiation exposure, false-positive biopsies), inappropriate drug treatment (opioids for fatigue-associated pain → dependence), polypharmacy |
- Relationship strain: Partners, family members struggle to understand an invisible illness
- Social isolation: ↓Energy for social interaction → withdrawal → loneliness → ↑depression
- Financial toxicity: Repeated medical consultations, investigations, inability to work, complementary/alternative medicine costs
- Doctor-shopping: Particularly in somatization — multiple consultations lead to contradictory advice, ↑investigation burden, ↑iatrogenic harm
The Deconditioning Spiral
One of the most important complications of chronic malaise is the deconditioning spiral:
Fatigue → ↓Activity → ↓Physical fitness → ↓Muscle mass + ↓Cardiovascular reserve → Activity feels even harder → More fatigue → Even less activity...
This is why graded physical activity (carefully titrated to the patient's current capacity) is a cornerstone of management for CFS/ME, fibromyalgia, and chronic fatigue states — it breaks the cycle by gradually rebuilding physiological reserve.
An often-overlooked category: the workup and management of malaise itself can cause harm.
| Iatrogenic Complication | Mechanism | Prevention |
|---|---|---|
| Radiation exposure | Repeated CXRs, CT scans ordered during prolonged workup → cumulative radiation dose | Follow evidence-based protocols; avoid repeat imaging without new clinical indication |
| False-positive results | Screening tests (ANA, tumour markers) have imperfect specificity → false positives lead to unnecessary further testing, biopsies, anxiety | Investigations should be judicious — false-positive results may lead to unnecessary invasive investigations and risks [8] |
| Unnecessary biopsies | False-positive imaging or blood tests → invasive procedures with bleeding, infection risk | Clinical reasoning before investigation; pre-test probability assessment |
| Drug side effects | Empirical antidepressants (SSRI → hyponatraemia in elderly, GI bleeding), empirical steroids (masking serious infection), unnecessary antibiotics (C. difficile, resistance) | Only prescribe when diagnosis supports it; monitor for side effects |
| Psychological harm of over-investigation | Repeated investigations reinforce illness behaviour in somatoform disorders; each normal result provides only temporary relief | Single coordinating physician; scheduled visits; CBT approach [8] |
| Diagnostic label harm | Premature labelling as "CFS/ME" may cause physician to stop looking for evolving organic disease; conversely, labelling as "psychosomatic" can be experienced as dismissive and damaging | Use diagnostic labels carefully; always maintain openness to reassessment |
5. Specific Complication Scenarios: High-Yield Exam Cases
These are clinical scenarios frequently tested in exams where malaise is the presenting symptom and the complication arises from mismanagement:
A 45-year-old presents with 3 months of progressive fatigue. The GP checks FBE: "mild anaemia, Hb 105" → told "iron deficiency" → given iron tablets → not followed up. Six months later: pancytopenia, DIC, diagnosed with APML with blast crisis.
What went wrong: Blood film not requested; ↓Hb not properly investigated (reticulocytes, iron studies, blood film); no follow-up.
Complication: Severe bleeding from DIC in APML [5] — potentially fatal.
A 35-year-old woman with 2 years of fatigue, intermittent nausea, and weight loss. Diagnosed with "depression and IBS." Started on SSRI. Later admitted to ICU with sepsis from pneumonia → refractory hypotension → serum cortisol undetectable → diagnosed with primary adrenal insufficiency.
What went wrong: Chronic adrenal insufficiency is non-specific, often misdiagnosed as depression [4]. Hyperpigmentation, postural hypotension, and electrolytes (hypoNa, hyperK) were not checked. No 9 am cortisol or SST.
Complication: Acute adrenal crisis precipitated by infection [4] — mortality 6–8% even when recognized.
A 55-year-old obese man complains of tiredness for years. Told "lose weight and exercise." Never asked about snoring or sleep quality. Involved in RTA after falling asleep at the wheel.
What went wrong: "Do not overlook a sleep disorder" [1]. Epworth Sleepiness Scale not performed. No polysomnography referral.
Complication: Road traffic accident — preventable with CPAP.
A 72-year-old with "general malaise and tiredness" for 2 weeks. Also mentions vague headache. ESR not checked. Three weeks later presents with sudden unilateral visual loss.
What went wrong: GCA systemic S/S: fever, anorexia, malaise [18] — malaise was the presenting symptom. ESR would have been markedly elevated. Urgent steroids would have prevented blindness.
Complication: Permanent blindness from arteritic AION [18] — irreversible.
| Principle | How It Prevents Complications |
|---|---|
| "Believe the patient's symptoms" [1] | Prevents dismissal → ensures investigation |
| "Be alert to depression including masked depression" [1] | Prevents missed depression → prevents suicide, functional disability |
| "Be alert for the classic endocrine traps" [1] | Prevents missed hypothyroidism and Addison's → prevents myxoedema coma and adrenal crisis |
| "Do not overlook a sleep disorder" [1] | Prevents missed OSA → prevents RTA, cardiovascular complications |
| Baseline investigation panel [1] | Catches anaemia, CKD, DM, liver disease, thyroid disease, electrolyte derangement before complications develop |
| Safety-netting and follow-up | Catches evolving disease on repeat assessment |
| Judicious investigations [8] | Prevents iatrogenic harm from false-positive results and unnecessary procedures |
High Yield Summary — Complications of General Malaise
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Malaise is a symptom, not a disease — complications arise from the underlying cause, from delayed/missed diagnosis, from chronic unexplained malaise itself, and from iatrogenic harm.
-
Most dangerous complications of missed diagnoses:
- Depression → suicide (lifetime risk ~15% in severe untreated depression)
- Adrenal insufficiency → acute adrenal crisis (shock, hypoglycaemia, death; often mis-diagnosed as depression [4])
- Hypothyroidism → myxoedema coma (mortality 20–50%)
- Leukaemia → DIC, neutropenic sepsis, death (fatigue precedes diagnosis by months [5])
- Occult cancer → metastatic disease
- GCA → permanent blindness [18]
- OSA → road traffic accidents, resistant HTN, cardiovascular death
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Chronic unexplained malaise complications: deconditioning spiral, secondary depression, functional disability, social isolation, financial toxicity, iatrogenic harm from over-investigation
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Prevention: Structured diagnostic approach (Murtagh's panel [1]), active screening for depression and sleep disorders, endocrine testing when clinically indicated, safety-netting, judicious investigation, and believing the patient's symptoms.
Active Recall - Complications of General Malaise
References
[1] Lecture slides: murtagh merge.pdf (p99, p101, p102 — Tiredness/chronic fatigue: Diagnostic tips) [2] Senior notes: Ryan Ho Endocrine.pdf (p80 — Type 2 DM presentation) [4] Senior notes: Ryan Ho Endocrine.pdf (p71 — Adrenal Insufficiency: clinical presentation, acute crisis) [5] Senior notes: Ryan Ho Haemtology.pdf (p51 — Acute Leukaemia; p78 — Primary Myelofibrosis) [6] Senior notes: Ryan Ho Psychiatry.pdf (p155 — Depressive Disorders: morbidity and mortality) [8] Senior notes: Ryan Ho Psychiatry.pdf (p199, p200 — Somatoform Disorders: judicious investigation) [10] Senior notes: Ryan Ho Respiratory.pdf (p81 — Cryptic TB: mortality) [11] Senior notes: Ryan Ho Haemtology.pdf (p29 — B12 deficiency: neurological complications) [18] Senior notes: Ryan Ho Neurology.pdf (p65 — Giant Cell Arteritis: complications, blindness)
High Yield Summary
Definition: General malaise = non-specific constitutional symptom of feeling unwell; reflects systemic process (cytokine-mediated sickness behaviour).
Top Causes (Murtagh's Probability Diagnoses) [1]:
- Stress and anxiety
- Inappropriate lifestyle and psychosocial factors
- Depression
- Viral / post-viral infection
- Sleep-related disorders (e.g. sleep apnoea)
Serious Not to Miss [1]: Cardiac (arrhythmia, cardiomyopathy, incipient CCF), Infection (hidden abscess, HIV/AIDS, hepatitis B and C, TB), Cancer, Anaemia, Haemochromatosis
Pitfalls [1]: Masked depression, Food intolerance, Coeliac disease, Chronic infection (Lyme disease, TB)
HK-Relevant Priorities: HBV (7–8% carrier), TB (intermediate burden), thalassaemia trait, NPC, rising T2DM/metabolic syndrome/NAFLD, depression
Pathophysiology: Pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) → brain via circumventricular organs/vagal afferents → hypothalamic sickness behaviour (fever, fatigue, anorexia, malaise) = adaptive response to conserve energy for immune response
Clinical Approach: Clarify symptom → systematic associated symptoms → constitutional review → systems review → thorough exam (don't skip lymph nodes, abdomen, skin) → targeted investigations based on clinical pointers
Red Flags: Unintentional weight loss, night sweats, persistent fever, lymphadenopathy, new mass, progressive symptoms, abnormal blood counts, age > 50 with new fatigue
High Yield Summary — DDx of General Malaise
- Most Common: Depression, anxiety, lifestyle factors, viral infection, sleep disorders [1]
- Must Not Miss: Cancer, leukaemia, HIV, TB, cardiac failure, anaemia, adrenal insufficiency, haemochromatosis [1]
- Often Missed: Masked depression, coeliac disease, food intolerance, chronic infection (TB, Lyme), hypothyroidism, CKD [1]
- HK-Specific: HBV (7–8%), TB (intermediate burden), thalassaemia, NPC, T2DM/metabolic syndrome, NAFLD
- Framework: Use Murtagh's probability → serious → pitfalls → rarities plus systems-based and tempo-based approaches
- Baseline Panel: FBE, ESR/CRP, blood sugar, electrolytes/Ca/Mg, RFT, LFTs, iron studies, FOB, TFTs, CXR [1]
- Always screen for depression — "masked depression" is the most commonly missed diagnosis in chronic malaise/fatigue
High Yield Summary — Diagnosis of General Malaise
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There are no diagnostic criteria for malaise itself — the task is to identify the cause via a structured algorithm.
-
4-Step Approach: Structured history → Focused examination → Baseline investigations → Targeted workup or psychiatric/sleep assessment.
-
Murtagh's Baseline Panel [1]: FBE, ESR/CRP, blood sugar, electrolytes/Ca/Mg, RFT, LFTs, iron studies, FOB, TFTs, CXR — this catches the vast majority of serious organic causes.
-
Key targeted investigations by system: Haematological (blood film, B12, BM biopsy), Infection (HIV, HBsAg, sputum AFB), Endocrine (9 am cortisol → SST, HbA1c, PTH), Autoimmune (ANA, anti-dsDNA, RF/ACPA, anti-tTG), Cardiac (ECG, BNP, Echo), Malignancy (CT TAP, biopsy).
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Always formally screen for depression (PHQ-9) and anxiety (GAD-7) — these are the most common causes and the most commonly missed.
-
Diagnostic criteria to know: MDD (SIG E CAPS, ≥ 5/9 for ≥ 2 weeks), CFS/ME (fatigue > 6 months + PEM + unrefreshing sleep), Somatic symptom disorder (DSM-5 criteria A–C), GCA (ACR ≥ 3/5), Adrenal insufficiency (SST pathway).
-
If everything is normal: Re-evaluate history, screen psych/sleep, review drugs, safety-net, consider CFS/ME only after genuine exclusion.
High Yield Summary — Management of General Malaise
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Core principle: Treat the cause, not the symptom. There is no "anti-malaise" drug.
-
General measures for ALL patients: Validate symptoms ("believe the patient") [1], lifestyle advice (diet and exercise) [1], medication review, sleep assessment ("do not overlook a sleep disorder" [1]), safety-netting.
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"Investigations are likely to be therapeutic and reassuring rather than diagnostic" [1] — a normal baseline workup itself is part of the management.
-
"Be alert to depression including masked depression" [1] — screen every patient with PHQ-9. SSRIs are first-line pharmacotherapy.
-
"Be alert for the classic endocrine traps: hypothyroidism and Addison disease" [1] — levothyroxine for hypothyroidism (start low, go slow); hydrocortisone ± fludrocortisone for adrenal insufficiency (treat acute crisis before investigations [4]).
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"Tiredness in absence of red flags is unlikely to have an organic cause" [1] — but still do the baseline panel, review in 4–6 weeks, and repeat tests if symptoms persist.
-
Iron deficiency: Oral iron + identify and treat the source of loss. Men/postmenopausal women → investigate for GI malignancy.
-
TB in HK: RIPE 2+4 months. Empirical anti-TB treatment can be life-saving in cryptic TB [10].
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CFS/ME: Diagnosis of exclusion. Pacing, CBT, sleep management, gradually increasing activity. No specific drug treatment.
-
Somatic symptom disorder: Single physician, scheduled visits, limit investigations (false positives cause harm) [8], CBT, treat comorbid depression/anxiety.
High Yield Summary — Complications of General Malaise
-
Malaise is a symptom, not a disease — complications arise from the underlying cause, from delayed/missed diagnosis, from chronic unexplained malaise itself, and from iatrogenic harm.
-
Most dangerous complications of missed diagnoses:
- Depression → suicide (lifetime risk ~15% in severe untreated depression)
- Adrenal insufficiency → acute adrenal crisis (shock, hypoglycaemia, death; often mis-diagnosed as depression [4])
- Hypothyroidism → myxoedema coma (mortality 20–50%)
- Leukaemia → DIC, neutropenic sepsis, death (fatigue precedes diagnosis by months [5])
- Occult cancer → metastatic disease
- GCA → permanent blindness [18]
- OSA → road traffic accidents, resistant HTN, cardiovascular death
-
Chronic unexplained malaise complications: deconditioning spiral, secondary depression, functional disability, social isolation, financial toxicity, iatrogenic harm from over-investigation
-
Prevention: Structured diagnostic approach (Murtagh's panel [1]), active screening for depression and sleep disorders, endocrine testing when clinically indicated, safety-netting, judicious investigation, and believing the patient's symptoms.
Foot/toe Pain
Foot or toe pain is discomfort arising from musculoskeletal, neurological, vascular, or dermatological conditions affecting the structures of the foot and toes, commonly caused by plantar fasciitis, metatarsalgia, gout, Morton's neuroma, or trauma.
Hand/wrist/elbow Pain
Hand, wrist, or elbow pain is a clinical presentation of discomfort in the upper extremity that may arise from musculoskeletal, neurological, or inflammatory conditions such as carpal tunnel syndrome, tendinopathy, arthritis, or epicondylitis.