Cough
Cough is a protective reflex involving forceful expulsion of air from the lungs to clear the airways of irritants, secretions, or foreign material.
Murtagh Diagnostic Strategy
| Category | Diagnosis | Key Discriminator | Cantonese Question / Finding | Probability |
|---|---|---|---|---|
| Probability Diagnosis | URTI / post-infectious cough | Acute onset, preceded by coryzal symptoms, self-limiting < 3 wk [1] | 「之前有冇傷風感冒先？」(Any preceding cold?) | ~45% |
| Post-nasal drip (UACS) | Throat clearing, nasal congestion, mucus dripping sensation [1] | 「有冇覺得有嘢由鼻腔流落喉嚨？」(Anything dripping down throat?) | ~15% | |
| Asthma | Episodic wheeze + cough, nocturnal, atopy, reversible airflow obstruction [7] | 「夜晚有冇喘鳴聲或者胸口好緊嗰種感覺？」(Nocturnal wheeze / chest tightness?) | ~10% | |
| GORD | Heartburn, acid taste, cough worse after meals or supine [9] | 「瞓低或者食完嘢之後咳多啲？有冇胃酸味？」 | ~5% | |
| Serious Not To Miss | Pneumonia | Acute fever + purulent sputum + SOB, tachypnoea is most sensitive sign [5] | 「有冇發高燒、痰好濃？」 | ~5% |
| Heart failure | Exertional dyspnoea, orthopnoea, PND, bilateral ankle oedema | 「瞓低有冇覺得抖唔到氣？腳有冇腫？」 | ~3% | |
| Lung carcinoma | Chronic smoker, haemoptysis, weight loss, clubbing, hoarseness [6] | 「有冇咳血？聲沙咗？體重輕咗？」 | ~1% | |
| Pulmonary TB | Chronic cough > 2–3 wk, night sweats, weight loss, contact history, indolent presentation [11] | 「有冇接觸過肺結核病人？夜晚出汗？」 | ~1% | |
| Pitfalls | Bronchiectasis | Daily mucopurulent sputum for months–years, clubbing, coarse crackles [12] | 「你係咪日日都有好多痰？手指甲有冇變形？」 | ~3% |
| Pertussis (whooping cough) | Paroxysmal cough with inspiratory whoop, post-tussive vomiting | 「咳完會唔會嘔？」(Post-tussive vomiting?) | ~2% | |
| Foreign body (esp. children) | Sudden onset, unilateral wheeze, choking history | 「有冇試過食嘢或者玩嘢嘅時候突然嗆親？」 | < 1% | |
| Masquerades | ACEI-induced cough | Dry cough starting weeks–months after starting ACEI, resolves on cessation [2] | 「你嗰隻血壓藥係咪叫X-pril？食咗幾耐先開始咳？」 | ~5% |
| Depression / anxiety → psychogenic cough | Cough disappears at night, no organic cause, associated stress | 「瞓著覺之後仲咳唔咳？」(Does it stop when you sleep?) | ~1% | |
| Trying to Tell Me Something? | Fear of lung cancer / TB | Patient with smoking history or TB contact presenting "just for a cough" | 「你最擔心啲咩？係唔係擔心肺有問題？」(What worries you most?) | ~10% |
6-Minute Consultation Structure
| Time | Task | Cantonese Key Phrases | Why It Scores Marks |
|---|---|---|---|
| 0:00–0:30 | Friendly greeting, introduce self, set agenda | 「你好呀，我係X醫生，今日由我同你傾。可唔可以叫你嘅全名呀？今日咩事嚟睇醫生呀？」(Hello, I'm Dr X, may I have your full name? What brings you here today?) | Rapport, open question; scores interpersonal marks from first second |
| 0:30–2:00 | HPI – symptom analysis of cough (onset, duration, nature, sputum, blood, triggers, diurnal, associated Sx, severity) | 「你咳咗幾耐呀？乾咳定有痰？痰係咩色？有冇血絲呀？幾時咳得最叻？有冇氣喘、發燒、鼻水、胸口痛？」 | Core marks in HPI completeness; duration separates acute from chronic cough [1] |
| 2:00–2:45 | Red flags + targeted review (haemoptysis, weight loss, night sweats → TB/Ca; SOB → asthma/HF; heartburn → GORD; medications especially ACEI) | 「有冇瘦咗？有冇夜晚出汗？有冇食緊邊隻藥，例如血壓藥？有冇胃酸倒流嗰種感覺？」 | Red flags = "must not miss" marks; ACEI-induced cough is a classic FM exam masquerade [2][3] |
| 2:45–3:30 | PMH, drug, allergy, FH, social Hx (smoking! occupation, contacts) | 「你有冇長期病？食咩藥？有冇藥物敏感？屋企人有冇類似情況？你有冇食煙？做咩工作？」 | Smoking status is pivotal for COPD/lung Ca; occupation for occupational lung disease [4] |
| 3:30–4:30 | ICE – uncover hidden agenda | 「你自己覺得咩原因令你咳呀？（Idea）你最擔心啲咩呀？（Concern）你今日嚟想我哋點樣幫到你？（Expectation）」 | Direct marks on Case Report Q3; hidden agenda often = fear of lung cancer or TB |
| 4:30–5:15 | Functional impact + psychosocial | 「咳嗽有冇影響你瞓覺？返工有冇影響？你心情點呀？屋企人有冇擔心？」 | Biopsychosocial marks (Q5b); shows patient-centredness |
| 5:15–5:45 | Summarise back, check understanding | 「等我總結吓：你咳咗X個禮拜，有/冇痰，冇血⋯⋯我有冇漏咗啲咩？」 | Summarising = high interpersonal marks |
| 5:45–6:00 | Signpost next step, safety net, close | 「我想幫你檢查吓，之後同你解釋。如果你咳血、好辛苦抖唔到氣，記得即刻去急症。多謝你今日嚟！」 | Safe closure + safety-net line |
Hidden agenda tip: Ask 「其實今日點解揀咗嚟睇醫生呀？」 — the patient may have had the cough for weeks but came TODAY because a relative was diagnosed with lung cancer, or because a colleague has TB. This question often reveals the real RFC.
| Domain | English Question | Cantonese Question | Why It Matters | If Positive, Think Of |
|---|---|---|---|---|
| Duration | How long have you been coughing? | 「你咳咗幾耐呀？」 | Acute ( < 3 wk) vs subacute (3–8 wk) vs chronic ( > 8 wk) determines DDx framework [1] | Acute → URTI, pneumonia; Chronic → asthma, COPD, TB, GORD, ACEI |
| Nature | Dry or productive? | 「乾咳定有痰咳出嚟？」 | Guides aetiology | Dry → post-nasal drip, asthma, ACEI, GORD; Productive → COPD, bronchiectasis, pneumonia [1] |
| Sputum | What colour/amount? | 「痰係咩色？幾多？」 | Purulent sputum → bacterial infection; rusty → pneumococcal [5] | Yellow/green → infection; pink frothy → APO |
| Haemoptysis | Any blood in sputum? | 「有冇咳血或者痰入面有血絲？」 | Red flag – must not miss TB, lung Ca, PE [1][6] | TB, lung Ca, bronchiectasis, PE |
| Fever | Any fever? | 「有冇發燒？」 | Infection vs non-infective | Pneumonia, TB, URTI |
| Night sweats / weight loss | Lost weight or night sweats? | 「有冇瘦咗？夜晚有冇標汗？」 | TB / malignancy red flags [6] | TB, lung Ca |
| Wheeze / SOB | Any wheezing or breathlessness? | 「有冇喘鳴聲？有冇氣喘？」 | Widespread polyphonic wheeze → asthma/COPD [7] | Asthma, COPD, HF |
| Diurnal pattern | Worse at night or morning? | 「幾時咳得最叻？夜晚定朝早？」 | Nocturnal / early morning → asthma; morning productive → bronchiectasis/COPD [1][8] | Asthma, GORD (supine), bronchiectasis |
| Triggers | Any triggers – cold air, dust, exercise? | 「有冇咩嘢會令你咳多啲？凍嘢、灰塵、做運動？」 | Allergens / exercise → asthma | Asthma, allergic rhinitis |
| Post-nasal drip | Runny nose, throat clearing? | 「有冇鼻水倒流？成日要清喉嚨？」 | Post-nasal drip / upper airway cough syndrome is a top cause of chronic cough [1] | Allergic rhinitis, sinusitis |
| GORD symptoms | Heartburn or acid taste? | 「有冇胃酸倒流？食完嘢有冇灼熱感？」 | GORD is one of the "big three" causes of chronic cough [9] | GORD |
| Drug history | Taking any medications, esp. BP meds? | 「有冇食緊藥？特別係血壓藥？」 | ACEI causes dry cough in ~20% of patients (↑ bradykinin) [2] | ACEI-induced cough |
| Smoking | Do you smoke? How much? How long? | 「你有冇食煙？食咗幾耐？一日幾多支？」 | Smoking → COPD, lung Ca; pack-years quantification [4] | COPD, lung Ca |
| Occupation | What is your job? | 「你做邊行？有冇接觸粉塵或者化學品？」 | Occupational lung disease (asbestosis, silicosis) [10] | Occupational lung disease, mesothelioma |
| Contacts | Anyone around you sick/coughing? | 「屋企人或者同事有冇人病咗？」 | TB contact, URTI cluster | TB, pertussis, URTI |
| Travel | Recent travel? | 「最近有冇去過旅行？」 | TOCC for infections | TB, novel respiratory infections |
| Atopy / FH | Any eczema, hay fever? Family asthma? | 「你有冇濕疹、鼻敏感？屋企人有冇哮喘？」 | Atopic triad supports asthma Dx | Asthma |
| Functional impact | Affecting sleep/work/daily life? | 「咳嗽有冇影響你瞓覺同返工？」 | Biopsychosocial assessment | Severity; psychological impact |
| Mood | Feeling stressed or low? | 「你心情點呀？有冇覺得好大壓力？」 | Psychogenic cough; depression masquerade | Psychogenic cough, somatisation |
Case Report Form Answer Builder
Template: Cough for [duration], [dry/productive], [+/− sputum colour], [+/− haemoptysis], [+/− fever], [+/− wheeze/SOB], [+/− weight loss/night sweats], [+/− post-nasal drip], [+/− GORD symptoms], [+/− smoking __ pack-years], [+/− ACEI use]. No/with red flags (haemoptysis / weight loss / night sweats). Functional impact on [sleep/work].
| Scenario | Best RFC Phrasing |
|---|---|
| Prolonged cough affecting sleep | "To find out why the cough is not resolving and to get treatment" |
| Fear of serious disease | "To exclude lung cancer / TB" |
| Medication side effect suspected | "To check if the blood pressure medication is causing the cough" |
| Acute illness | "To get treatment for an acute respiratory infection" |
Tip: The RFC is what the patient wants — phrase it from their perspective, not a medical label.
| Component | Example Wording for Case Report |
|---|---|
| Idea | "Patient thinks the cough may be due to smoking / catching a cold / allergy" |
| Concern | "Patient is worried it could be lung cancer / TB / something serious" |
| Expectation | "Patient wants a chest X-ray / antibiotics / cough medicine / to stop the blood pressure medication" |
Pick based on stem clues:
| Stem Clue | Most Likely Dx | Minimum Supporting Evidence |
|---|---|---|
| Acute cough + coryzal Sx + no red flags | Acute URTI | < 3 wk duration, rhinorrhoea, sore throat, no consolidation signs |
| Chronic smoker + productive cough + SOB | COPD | > 20 pack-years, progressive dyspnoea, ↓FEV1/FVC [4] |
| Young atopic patient + episodic wheeze + night cough | Asthma | Atopy, reversible airflow obstruction, polyphonic wheeze [7] |
| Chronic cough + ACEI use | ACEI-induced cough | Temporal relationship with ACEI initiation; dry cough; resolves 1–4 wk after stopping [2] |
| Chronic cough + heartburn | GORD-related cough | Heartburn, worse supine/post-prandial [9] |
| DDx | One Key Discriminator |
|---|---|
| Post-nasal drip / UACS | Throat clearing, nasal congestion, cobblestone pharynx |
| Asthma (if not primary Dx) | Episodic wheeze, response to bronchodilator |
| GORD | Heartburn, acid brash, worse after meals/supine |
| TB | Chronic cough > 3 wk, night sweats, weight loss, TB contact |
| Lung Ca | Smoker, haemoptysis, weight loss, clubbing |
| ACEI cough | Dry cough, temporal link to ACEI |
Choose the 3 that best fit the patient's profile in the stem. Avoid repeating the most likely Dx.
| Domain | Example |
|---|---|
| Biological | Chronic cough causing sleep disturbance / rib pain / urinary stress incontinence |
| Psychological | Anxiety about serious disease (lung cancer / TB); low mood from chronic symptoms |
| Social | Cough affecting work performance / social embarrassment / inability to care for family; smoking dependence |
| Diagnosis/DDx | Best Supporting Physical Sign | How to Elicit | Why It Supports This Dx |
|---|---|---|---|
| URTI | Pharyngeal erythema / tonsillar exudate | Inspect oropharynx with tongue depressor & torch | Confirms upper respiratory inflammation |
| Asthma | Widespread bilateral polyphonic expiratory wheeze [7] | Auscultate both lung fields during forced expiration | Indicates reversible small airway obstruction |
| COPD | Barrel chest + prolonged expiratory phase + decreased breath sounds | Inspect AP diameter; auscultate | Indicates hyperinflation and chronic airflow limitation [4] |
| Pneumonia | Bronchial breathing + dullness to percussion + increased vocal resonance over affected area | Percuss and auscultate systematically | Indicates consolidation [5] |
| TB | Apical crackles on auscultation (often unremarkable in early disease) | Auscultate apices bilaterally | Predilection for upper lobes; but note exam may be normal — CXR is the key investigation [11] |
| Lung Ca | Finger clubbing | Inspect nails for loss of nail-fold angle (Schamroth's sign) | Associated with lung Ca, bronchiectasis, ILD; not COPD [6] |
| GORD-related cough | No reliable respiratory sign in brief FM station | Epigastric tenderness may be present but non-specific | Diagnosis is clinical (PPI test) and by history [9] |
| ACEI cough | No physical sign | — | Diagnosis is purely by history (drug–symptom temporal relationship); no sign [2] |
| Post-nasal drip | Cobblestone appearance of posterior pharynx | Inspect posterior pharynx | Lymphoid hyperplasia from chronic post-nasal drainage |
| Heart failure | Bilateral basal fine inspiratory crackles + displaced apex beat + elevated JVP | Auscultate lung bases; palpate apex; inspect JVP | Pulmonary congestion from raised LVEDP |
| Bronchiectasis | Coarse inspiratory crackles (late/pan-inspiratory) + finger clubbing [12] | Auscultate; inspect fingers | Chronic airway infection and dilation |
Top Traps That Lose Marks
- Forgetting to ask about ACEI — classic FM exam masquerade; a dry cough in a hypertensive patient on ACEI is almost always tested [2].
- Not asking smoking history with pack-years — without this, you cannot justify COPD or lung Ca.
- Skipping ICE — direct marks on Q3. Students often run out of time because they over-investigate HPI.
- Listing diagnoses without discriminators — the Case Report wants you to justify each DDx with one key feature.
- Confusing the RFC with the chief complaint — the CC is "cough for 3 weeks"; the RFC might be "worried about lung cancer because uncle just diagnosed."
- Not screening for TB — in HK, TB remains prevalent; always ask about contact, night sweats, weight loss [11].
- Forgetting GORD and post-nasal drip — the "big three" causes of chronic cough (UACS, asthma, GORD) are high-yield [1].
Red Flags — Must Not Miss
- Haemoptysis → urgent CXR → ? lung Ca / TB / PE
- Significant weight loss / night sweats → TB / malignancy
- Stridor → upper airway obstruction — urgent ENT referral [13]
- Massive haemoptysis ( > 100 mL/day) → emergency; lie on bleeding side, ICU [1]
- New hoarseness + cough in smoker → recurrent laryngeal nerve palsy from lung Ca
- Children: sudden choking + unilateral wheeze → foreign body aspiration — urgent bronchoscopy [14]
Safety-Net Closing Line
「如果你咳血、抖唔到氣、或者發高燒，請即刻去急症室。我會安排照X光同埋覆診跟進。」 ("If you cough up blood, can't breathe, or develop high fever, go to A&E immediately. I will arrange a CXR and follow-up.")
High Yield Summary
What to ASK: Duration (acute vs chronic), nature (dry vs productive), sputum colour, haemoptysis, fever, night sweats, weight loss, wheeze/SOB, post-nasal drip, GORD symptoms, ACEI use, smoking pack-years, TB contact, occupation, ICE.
What to WRITE: Chief complaint with duration + key positives/negatives → RFC from patient's perspective → ICE verbatim → Most likely Dx with ≥2 supporting features → 3 DDx each with 1 discriminator → 1 Bio + 1 Psycho + 1 Social problem → 1 physical sign with method.
What NOT to MISS: ACEI cough (masquerade), TB (HK-prevalent), lung Ca in smokers, GORD as chronic cough cause, foreign body in children. Always do ICE — it is directly marked.
Active Recall - Family Medicine Clinical Test
[1] Senior notes: Maksim Medicine Notes.pdf (Respiratory medicine – Cough section, p.280) [2] Senior notes: Block A - Clinical Pharmacology of anti-HT and anti-HF medications.pdf (ACEI side effects – cough and angioedema) [3] Lecture slides: GC 041. Cough in a chronic smoker_COPD; smoking cessation.pdf [4] Lecture slides: GC 041. Cough in a chronic smoker_COPD; smoking cessation.pdf [5] Lecture slides: GC 052. Fever and purulent sputum.pdf [6] Past papers: 2025 Fourth Summative SAQ.pdf (Q3 – 60-year-old smoker with cough and blood-stained sputum, p.5) [7] Senior notes: Adrian Lui Pediatrics Notes.pdf (Asthma diagnosis – polyphonic wheeze, spirometry criteria, p.171) [8] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (Cough – onset, nature, triggering/exacerbating factors, p.113) [9] Senior notes: Ryan Ho GI.pdf (GERD – clinical features, PPI test, p.58); Lecture slides: MBBS Final MB (Surgery) (Felix PY Lai).pdf (GERD extra-oesophageal symptoms – chronic cough, p.354) [10] Lecture slides: GC 083. Shortness of breath in a construction site worker.pdf [11] Senior notes: Gen Clerk Anaes + Microbiology Summary.pdf (Clinical presentation of TB, p.33) [12] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (Bronchiectasis – signs and symptoms, p.182) [13] Lecture slides: GC 220. Upper airway obstruction and tracheostomy.pdf [14] Senior notes: MBBS Final MB (Pediatrics) (Felix PY Lai).pdf (Croup, foreign body aspiration, p.138); Lecture slides: GC 141. A child with cough acute and chronic cough in children.pdf
Most Common HK Primary Care Symptoms
The 34 most common symptom presentations in Hong Kong primary care, ranked from local practice data.
Skin Rash
A skin rash is a visible change in the color, texture, or appearance of the skin, often manifesting as redness, bumps, or lesions, resulting from inflammatory, infectious, allergic, or systemic causes.