Reasoning GP · Algorithm · 1-page summary
Chronic cough in adults (≥8 weeks)
For: adults with cough ≥8 weeks, face to face or remote. Not for: children (childhood cough) or cough <3 weeks (acute cough). Immunosuppressed → block 2.
Core rule: stop any ACE inhibitor and get a chest X-ray for every adult; exclude cancer and TB before symptomatic treatment; then one targeted trial at a time, never all three together.
0Stop — call 999 now — before any history
- Stridor or upper-airway obstruction; brisk, ongoing or airway-threatening haemoptysis (judge the patient, not volume); anaphylaxis; sepsis with cough and fever → 999
- Breathless at rest with severe hypoxia or SpO₂ below the patient's own target, exhaustion or cyanosis; acute severe asthma; chest pain with haemodynamic compromise or syncope → 999
- While waiting: ABCDE, sit up, controlled oxygen (94–98%; 88–92% if at risk of hypercapnia), SpO₂, exact onset, hand over. Do not examine a stridulous throat or delay transfer for a CXR or spirometry.
1Triage — duration, then the drug chart
| Finding | Action |
|---|---|
| <3 weeks | Acute — not this pathway. |
| 3–8 weeks | Post-infectious; consider pertussis (paroxysms, whoop). |
| ≥8 weeks | Chronic → this pathway and a CXR, even if “post-viral”. |
| ACE inhibitor | Cough in 10–15%. Stop if appropriate; ARB if indicated (BP, renal function, K⁺). Also sitagliptin, irritant inhalers. |
2Screen — one row is enough
- Cancer (NG12): unexplained haemoptysis ≥40, or CXR suggesting cancer → Suspected cancer pathway. ≥40 with unexplained cough plus another unexplained symptom, or ever smoked, or asbestos → CXR ≤2 weeks. Hoarse ≥45 (persistent) → head and neck; dysphagia → upper GI pathway.
- TB: fever, night sweats and weight loss, or 3 weeks' cough with TB risk (high-incidence country, contact, homeless, prison) → urgent CXR, 3 sputum samples, Same-day TB service
- Immunosuppressed with new or changed cough → Same-day CXR, FBC, exertional SpO₂, specialist; hypoxic or septic → 999; neutropenic fever → hospital now.
- Aspiration (coughing on swallowing, recurrent consolidation) or hoarseness >3 weeks → Urgent CXR, swallow assessment, ENT or upper GI.
- Bronchiectasis or ILD (daily sputum, recurrent infections, clubbing, crackles) → Urgent CXR; respiratory (urgent if ILD), even if CXR normal.
- Heart failure (orthopnoea, oedema, raised JVP): breathless at rest → Same-day; else NT-proBNP, ECG: >2000 ng/L → echo ≤2 weeks, 400–2000 → echo ≤6 weeks
3Assess — CXR is not optional
☐ Weight, RR, SpO₂ rest and exertion, pulse, temp ☐ Voice, nose, throat, chest, clubbing, nodes, JVP ☐ CXR (unless a recent film and no change) ☐ Spirometry with reversibility; FeNO if available; peak-flow diary ☐ FBC with eosinophils, U&E, TFTs; sputum if productive
Not here: routine CT, bronchoprovocation, serum ACE, blanket allergy tests.
4Classify — only once the CXR is normal and cancer and TB excluded
- ACE inhibitor — dry, tickly; improves over several weeks after stopping; not always the cause.
- Upper airway — throat clearing, dripping sensation, rhinitis, cobblestoned pharynx → 5a.
- Asthma / eosinophilic — nocturnal, cold air, exercise; spirometry often normal. FeNO ≥50 ppb, reversibility ≥12% and ≥200 ml, PEF variability ≥20% or raised eosinophils → 5c.
- Reflux — only with heartburn, regurgitation or convincing reflux features → 5b.
- Productive (bronchiectasis, COPD) → sputum culture, airway clearance; no ICS or PPI trials.
- Unexplained after adequate trials — state the uncertainty, refer (block 6). Hypersensitivity only after traits treated.
5Treat today — one trial at a time, full length
- First: stop the ACE inhibitor; CXR arranged; smoking cessation. No trial before the CXR is back.
- 5a Intranasal steroid (e.g. mometasone 2 sprays each nostril daily, technique away from septum) ± cetirizine 10 mg if allergic, saline → review 4–6 weeks.
- 5b Consider PPI (e.g. omeprazole 20 mg daily before food) + reflux measures; not twice-daily or high-dose. 5c Low-dose ICS per formulary, review ~4 weeks, stop if no benefit; SABA only if wheeze.
- Not: antibiotics without infective indication, codeine instead of diagnosis, neuromodulators (specialist). Doses: NICE/SPC, BNF, local formulary.
6Refer routinely
- Unexplained after adequate trials → respiratory, listing each trial; refractory or hypersensitivity → cough clinic or SALT.
- Asthma tests inconclusive → respiratory or diagnostic hub; better away from work → occupational lung service.
- Reflux not responding to PPI → gastroenterology; laryngeal cause → ENT.
- Sooner than 3–6 months if abnormal CXR, persistent haemoptysis, desaturation, recurrent pneumonia or unclear diagnosis.
7Never reassure by
- A normal CXR — it excludes neither cancer, bronchiectasis nor ILD.
- “Smoker's cough” or COPD without imaging and spirometry.
- “Post-viral” at 8 weeks.
- “Reflux” or “silent reflux” from cough, throat clearing or hoarseness alone.
- “Not asthma” on normal spirometry or a normal FeNO.
- A “failed” trial stopped early, with poor technique, or run with others.
8Safety-net — say it, then document it
999 “Call 999 for noisy or difficult breathing, or brisk ongoing bleeding when you cough.” Same day “Contact us today if you cough up blood, lose weight, get fevers or night sweats, are breathless at rest, or hoarse beyond 3 weeks.” Repeat the CXR if the cough changes.
Remote or OOH: face to face if productive or bloody, breathless, weight loss, fever, night sweats, hoarse, dysphagia, SpO₂ or chest unchecked, immunosuppressed or TB risk. Never sign off until the CXR is seen.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies; NG12 criteria documented absent
SpO₂ normal at rest and on exertion; CXR done and normal
ACE inhibitor stopped; pack-years, asbestos, TB risk recorded
One trait treated for its full length; review booked, named reviewer
Safety-net given and documented
Summary of the full Reasoning GP chronic cough algorithm, which holds the detail and evidence. Sources: BTS chronic cough (2023); NICE NG12 (April 2026), NG245, NG115, NG106, NG33, CG184; MHRA. Clinical reference — follow local TB-notification and prescribing policies; check doses: NICE/SPC, BNF.