What makes a cough 'chronic'?

A cough is classified as chronic when it has been present for more than eight weeks in adults (more than four weeks in children). Between three and eight weeks it is called subacute — often post-infectious, frequently following a viral respiratory illness, pertussis, or Mycoplasma pneumoniae. Subacute cough usually resolves without specific treatment though it can be frustrating for patients. A cough that has persisted beyond eight weeks needs a structured assessment — most have a treatable cause, though the cause is not always immediately obvious and empirical treatment trials are often needed.

Could my chronic cough be caused by my blood pressure medication?

Yes — ACE inhibitors (ramipril, perindopril, enalapril, lisinopril) cause a dry, tickling cough in 5–35% of users, and this is a class effect. It typically starts within weeks of initiating the medication but can develop months or years later. The cough is often worse at night and does not produce sputum. Importantly, it resolves within 1–4 weeks of stopping the ACE inhibitor (sometimes up to 12 weeks). Switching to an ARB (candesartan, irbesartan, telmisartan) provides equivalent blood pressure and heart protection without causing cough. This is always the first step to check in any person on an ACE inhibitor with a new cough.

Why might my cough be caused by reflux if I don't have heartburn?

Gastro-oesophageal reflux can cause cough even when there is no burning or heartburn — this is sometimes called laryngopharyngeal reflux or 'silent reflux.' Tiny amounts of stomach acid or non-acid material reach the back of the throat, triggering the cough reflex without causing the typical heartburn sensation. Clues include a cough that worsens when lying flat, after meals, or after alcohol; a persistent throat-clearing sensation; hoarseness in the mornings; or a bitter taste. Treatment includes twice-daily PPI for 8–12 weeks alongside lifestyle measures — weight loss, head-of-bed elevation, avoiding meals within 3 hours of sleep.

What is refractory chronic cough and how is it treated?

Refractory chronic cough (RCC) is diagnosed when cough persists despite thorough investigation and adequate treatment of all identified causes. The emerging understanding is that RCC often reflects cough hypersensitivity syndrome — increased sensitivity of the laryngeal cough reflex to normal stimuli like cold air, talking, or perfume. Treatment has two main arms. Speech pathology cough suppression therapy — a structured program teaching laryngeal control techniques — has randomised trial evidence showing approximately 40% reduction in cough frequency and is recommended by the European Respiratory Society. For persistent cough, neuromodulators including gabapentin and low-dose morphine (off-label) provide additional benefit.

When does chronic cough need urgent investigation for cancer?

A smoking history is the most important risk factor for lung cancer presenting as cough. Any current or ex-smoker aged 45 or over with a new or changed cough should have a chest X-ray arranged promptly; if normal and symptoms persist, CT chest is the next step. Other red flags warranting urgent investigation regardless of smoking status include: coughing up blood (haemoptysis, even small amounts), unexplained weight loss, hoarseness lasting more than three weeks, difficulty swallowing, unexplained fatigue or fevers, and palpable lymphadenopathy. Eligible ex- and current smokers aged 50–70 with 30 or more pack-years of smoking history can access the Lung Cancer Screening Program for biennial low-dose CT.

Chronic cough

Chronic cough: causes, investigations, and treatment in AU general practice

By Dr HB Lo, FACRRM Reviewed 22 May 2026 10 min read

Chronic cough — beyond eight weeks in adults — affects ~10% of the population. In a non-smoker with a normal chest X-ray, the top three causes are upper airway cough syndrome, cough-variant asthma, and gastro-oesophageal reflux; together over 90% of cases.

Stop any ACE inhibitor first, then arrange spirometry and chest X-ray, and trial empirical treatment for the most likely cause over 4–8 weeks. Red flags — haemoptysis, weight loss, hoarseness, smoking history — warrant urgent investigation.

When thorough workup finds no cause, speech pathology cough suppression therapy and neuromodulator medications manage refractory chronic cough.

A cough that has been present for more than eight weeks is classified as chronic. It affects approximately 10% of the adult population, is twice as common in women as in men, and carries a quality-of-life impact that is frequently underestimated by clinicians — validated scoring tools show that patients with refractory chronic cough report wellbeing scores comparable to severe COPD or heart failure. Sleep disruption, social embarrassment, urinary incontinence, and cough-related syncope or rib fractures are documented consequences.

The clinical challenge is that chronic cough is frequently multifactorial and may not respond to standard treatments in sequence. eTG respiratory guidelines and the European Respiratory Society 2020 guidelines both recommend a structured empirical approach: identify and address the most likely cause, reassess, then move to the next most likely cause. In a non-smoker, off all ACE inhibitors, with a normal chest X-ray, the cause is identified in the vast majority of cases — upper airway cough syndrome, asthma or cough-variant asthma, and gastro-oesophageal reflux account for over 90%.

A. Core clinical — the AU general-practice framework

Definitions

Acute cough — less than 3 weeks; typically viral upper respiratory tract infection
Subacute cough — 3–8 weeks; often post-infectious, particularly post-viral, pertussis, or Mycoplasma
Chronic cough — >8 weeks in adults (>4 weeks in children — a different threshold)
Refractory chronic cough (RCC) — cough persisting despite adequate treatment of all identified causes
Unexplained chronic cough (UCC) — chronic cough with no identifiable cause after thorough workup
Cough hypersensitivity syndrome — the emerging construct unifying RCC and UCC: an abnormally sensitive laryngeal cough reflex triggered by minimal stimuli (cold air, talking, perfume, dry environments)

Red flags — assess first at every presentation

Per eTG and RACGP guidance:

Haemoptysis — even blood-tinged or streaky; warrants urgent chest X-ray then CT and respiratory or ENT review
Unexplained weight loss — malignancy until proven otherwise
Smoker or ex-smoker aged ≥45 years with a new or changed cough
Hoarseness lasting more than 3 weeks
Dysphagia or odynophagia
Recurrent pneumonia in the same lobe
Lymphadenopathy — cervical or supraclavicular
Night sweats and fevers — consider tuberculosis, lymphoma
Occupational exposures — silica, asbestos, engineered stone (banned July 2024), bird/animal protein, grain dusts

Any red flag warrants prompt chest X-ray as a minimum; most also warrant early CT chest and specialist referral.

Differential diagnosis — the systematic list

The three most common causes in a non-smoker, off ACE inhibitor, with a normal chest X-ray and spirometry:

Upper airway cough syndrome (UACS / post-nasal drip) — allergic rhinitis, non-allergic rhinitis, chronic rhinosinusitis; sensation of mucus dripping down the back of the throat; frequent throat-clearing
Asthma and cough-variant asthma — cough as the sole or dominant symptom of asthma; normal spirometry is possible; FeNO elevation or methacholine-provoked airway hyperresponsiveness confirms the diagnosis
Gastro-oesophageal reflux disease (GORD) and laryngopharyngeal reflux — may be silent (no heartburn); cough worsened lying flat or postprandially

Less common causes to consider:

Non-asthmatic eosinophilic bronchitis — sputum eosinophilia, normal spirometry, no airway hyperresponsiveness; responds to inhaled corticosteroid
ACE inhibitor cough — class effect in 5–35% of users; resolves within 1–12 weeks of cessation
Post-infectious cough — pertussis (notifiable disease), Mycoplasma, post-viral airway hyperresponsiveness
Bronchiectasis — productive cough, recurrent chest infections, HRCT diagnostic
Smoking-related — chronic bronchitis, early COPD
Lung cancer — new or changed cough in smoker or older adult
Interstitial lung disease — dry cough with exertional dyspnoea; Velcro crackles
Heart failure — nocturnal and positional cough, orthopnoea, peripheral oedema
Tuberculosis — productive cough >3 weeks, B-symptoms, risk factors; notifiable disease
Foreign body — acute onset particularly in children

Diagnostic algorithm

ERS 2020 chronic cough guidelines recommend a structured sequential approach:

Detailed history and examination — duration, character (dry vs productive), timing (nocturnal, postprandial, positional), triggers, associated symptoms (nasal symptoms, heartburn, wheeze, dyspnoea)
Stop ACE inhibitor first — if the patient is on an ACE inhibitor, switch to an ARB and reassess after 4–6 weeks (allow up to 12 weeks); this is the first intervention before any further workup
Chest X-ray and spirometry with pre- and post-bronchodilator response
Empirical sequential trials based on most likely diagnosis:
- UACS suspected — intranasal corticosteroid (mometasone, fluticasone) once daily plus saline nasal rinse ± antihistamine for 4–6 weeks
- Asthma / cough-variant asthma suspected — ICS or ICS-LABA trial for 4–8 weeks; PEF diary; consider FeNO measurement if accessible; spirometry may be normal — positive response to ICS confirms cough-variant asthma
- GORD suspected — PPI twice daily for 8–12 weeks plus lifestyle measures (weight loss, head-of-bed elevation, no meals within 3 hours of lying down, reduce alcohol and fatty foods)
If no response — re-evaluate; consider HRCT chest, bronchoscopy, ENT review (laryngoscopy), 24-hour pH/impedance monitoring, FeNO, methacholine challenge
If exhaustive workup negative — diagnose RCC/UCC and manage accordingly

B. Evidence for common cause treatments

Upper airway cough syndrome

Intranasal corticosteroid — mometasone or fluticasone propionate — is first-line for UACS across all causes (allergic rhinitis, non-allergic rhinitis, chronic sinusitis). The evidence supports 4–8 weeks of regular use before judging response. Saline nasal irrigation (0.9% saline daily via Neti pot or squeeze bottle) has independent randomised trial evidence and is inexpensive and well-tolerated. NPS MedicineWise recommends intranasal corticosteroid as preferred to oral antihistamines for the nasal symptoms driving UACS.

Cough-variant asthma

ICS alone or ICS-LABA combination reliably resolves cough in cough-variant asthma within 4–8 weeks. Normal spirometry does not exclude cough-variant asthma — FeNO ≥25 ppb or positive methacholine challenge confirms airway inflammation or hyperresponsiveness. A positive treatment response is itself diagnostically informative. eTG and Lung Foundation Australia asthma management resources provide AU-specific prescribing guidance.

PPI twice daily for 8–12 weeks is the pharmacological mainstay, though the evidence for PPI in GORD-cough is less robust than for typical GORD symptoms — particularly when there is no heartburn or regurgitation. Lifestyle measures are as important as medication: weight reduction has robust evidence, head-of-bed elevation reduces overnight acid exposure, and avoiding late meals prevents postprandial reflux. eTG notes that the majority of GORD-cough improvement occurs from lifestyle, and PPI should not substitute for these measures.

Non-asthmatic eosinophilic bronchitis

ICS is effective when sputum eosinophilia is confirmed. Unlike asthma, spirometry and airway hyperresponsiveness testing are normal. This diagnosis requires sputum analysis or specialist assessment and should not be assumed empirically.

C. Refractory chronic cough — when the standard approach fails

Cough hypersensitivity syndrome

When all identified causes have been treated adequately and cough persists, cough hypersensitivity syndrome is the prevailing explanatory framework. The laryngeal cough reflex becomes sensitised — responding to non-noxious stimuli (cold air, talking, perfume, smoke, exercise) that would not cause cough in unaffected individuals. This is not a diagnosis of exclusion made hastily — adequate treatment trials for UACS, asthma, and GORD each require weeks to months.

Speech pathology cough suppression therapy

The intervention with the strongest research support for RCC is speech pathology cough suppression therapy (also called physiotherapy cough suppression or behavioural cough therapy). The program includes:

Laryngeal control techniques — breathing exercises to break the cough cycle
Psychoeducation — explaining the cough hypersensitivity model to reduce anxiety about the symptom
Identification and management of triggers
Vocal hygiene advice — hydration, humidification, reducing throat-clearing

Randomised controlled trials demonstrate approximately 40–75% reduction in cough frequency and significant quality-of-life improvement. ERS 2020 guidelines give this a Grade A recommendation. In Australia, access to cough-trained speech pathologists can be limited — private referral is often required.

Neuromodulator pharmacotherapy

Gabapentin 300–1800 mg/day — off-label for cough; one RCT (Ryan, Lancet 2012) demonstrated significant cough score reduction; sedation and dizziness are common; titrate slowly; PBS Authority Required for neuropathic pain, not for cough (off-label, general practice prescribing is feasible)
Pregabalin 75–150 mg twice daily combined with speech pathology — the Vertigan trial showed combination superior to either alone
Low-dose morphine 5–10 mg twice daily — off-label; robust evidence (Morice AJRCCM 2007); very effective for severe RCC; constipation and drowsiness common; requires SafeScript monitoring; reserve for specialist-directed refractory cases
Gefapixant 45 mg twice daily — P2X3 receptor antagonist; TGA-registered 2024 for adults with RCC; COUGH-1 and COUGH-2 phase 3 trials showed modest but significant cough frequency reduction; taste disturbance (dysgeusia) in approximately 50%; not PBS-listed as at May 2026 — private prescription approximately $300+ per month

Codeine and over-the-counter antitussives are not recommended for chronic cough. Codeine was rescheduled to Schedule 4 in Australia in 2018. Evidence for OTC antitussives in chronic cough is minimal. Per NPS MedicineWise and eTG, they should not be routinely recommended.

D. Australian operations

MBS items

Standard GP consultations: 23, 36, 44
Spirometry in rooms (item 11506) — requires GP accreditation; pre- and post-bronchodilator; essential for asthma assessment
GPCCMP (items 965 and 967) — applicable for chronic respiratory conditions (chronic cough, asthma, bronchiectasis, COPD) expected to last 6+ months
Aboriginal and Torres Strait Islander Health Assessment (715) — every 9 months; includes respiratory review
Lung Cancer Screening Program — eligible patients aged 50–70 with ≥30 pack-year smoking history, currently smoking or quit within 10 years; biennial low-dose CT available through the national LCSP (launched July 2025)
Telehealth: 91790, 91890 for established-relationship telehealth GP consultations

PBS prescribing

Intranasal corticosteroid (mometasone, fluticasone) — General Schedule for allergic rhinitis
ICS and ICS-LABA combinations (budesonide, fluticasone, beclomethasone, salmeterol, formoterol combinations) — Authority Required (Streamlined) for asthma
PPIs (pantoprazole, esomeprazole, omeprazole) — General Schedule at standard doses; Authority for higher doses in severe oesophagitis
Gabapentin — Authority Required (Streamlined) for neuropathic pain; off-label for cough (prescriber discretion)
Low-dose morphine — General Schedule for pain; off-label for cough requires SafeScript documentation; consider respiratory specialist co-management
Gefapixant — not PBS-listed as at May 2026; private prescription

Notifiable diseases

Pertussis and tuberculosis are both notifiable conditions in all Australian states and territories. Pertussis should be considered in subacute cough with paroxysms, post-tussive vomiting, or inspiratory whoops — PCR is the preferred test within three weeks of symptom onset; serology after that. TB is considered in any person with productive cough beyond three weeks plus fever, night sweats, weight loss, or relevant risk factors (migration from endemic country, prior incarceration, HIV, immunosuppression, recent close contact).

Referral pathways

Respiratory physician — abnormal spirometry, refractory cough, suspected interstitial lung disease, bronchiectasis, suspected malignancy, complex COPD
ENT — persistent UACS unresponsive to medical management, hoarseness beyond 3 weeks, suspected laryngeal pathology
Gastroenterology — refractory GORD-cough, dysphagia, weight loss (24-hour pH/impedance, manometry, gastroscopy)
Speech pathology — RCC, UCC; cough suppression therapy
Cardiology — suspected heart failure or cardiac-origin cough

E. Special populations

Children. The chronic cough definition in children is >4 weeks (not 8). The most important AU-specific paediatric entity is protracted bacterial bronchitis (PBB) — a wet cough persisting more than four weeks that responds to two weeks of amoxicillin-clavulanate; recognised by RACGP and respiratory paediatricians as a distinct condition and a risk factor for bronchiectasis if recurrent. Do not use PPI empirically in children with cough — evidence is poor and adverse effects are real. Habit cough (Tourettism-like, disappears with sleep or distraction) is seen in school-age children and is managed with behavioural approaches.

Pregnant women. ACE inhibitors are contraindicated in pregnancy regardless of cough. Post-infectious cough from pertussis warrants empirical azithromycin if within three weeks of onset, and notification. Intranasal corticosteroids (budesonide, fluticasone) are safe in pregnancy for rhinitis management. PPI use should be minimised and limited to lower doses when possible.

Smokers and ex-smokers. Smoking cessation is the most effective intervention for smoking-related cough — chronic bronchitis cough typically resolves within 3 months of quitting. Do not reassure smokers with persistent cough that it is “just the smoking” without ensuring cancer screening is appropriately applied.

Occupational cough. Consider occupation in every chronic cough assessment. High-risk occupations: engineered stone fabrication (silicosis; engineered stone banned July 2024 in Australia), farming (farmer’s lung, hypersensitivity pneumonitis), healthcare (occupational asthma from latex, cleaning agents), mining. Refer to occupational and environmental medicine physician; consider workers’ compensation pathways.

When to escalate

Haemoptysis, unexplained weight loss, hoarseness, or dysphagia — urgent GP review; chest X-ray same week; CT chest and specialist referral
Any smoker with a changed or new cough — urgent chest X-ray; consider CT
Failed empirical trials for UACS, asthma, and GORD — respiratory physician or respiratory physician plus ENT and gastroenterology
Suspected pertussis or tuberculosis — isolate, notify, treat
Refractory cough with severe quality-of-life impact — speech pathology and respiratory specialist co-management; consideration of neuromodulator therapy

What this article is and is not

This is general health information based on current Australian guidelines — Therapeutic Guidelines (eTG), RACGP guidance, ERS 2020 chronic cough guidelines, and Lung Foundation Australia resources. It is not personal medical advice and does not create a doctor–patient relationship. The management of chronic cough frequently requires in-person assessment, spirometry, and empirical treatment trials guided by an individual clinical assessment. Decisions about investigation and treatment are made with your own GP and treating specialists.

For reliable consumer information: HealthDirect — Cough, Better Health Channel — Cough, Lung Foundation Australia.

For respiratory crisis or medical emergency: call 000.

Sources cited

Frequently asked questions

What makes a cough 'chronic'?

A cough is classified as chronic when it has been present for more than eight weeks in adults (more than four weeks in children). Between three and eight weeks it is called subacute — often post-infectious, frequently following a viral respiratory illness, pertussis, or Mycoplasma pneumoniae. Subacute cough usually resolves without specific treatment though it can be frustrating for patients. A cough that has persisted beyond eight weeks needs a structured assessment — most have a treatable cause, though the cause is not always immediately obvious and empirical treatment trials are often needed.
Could my chronic cough be caused by my blood pressure medication?

Yes — ACE inhibitors (ramipril, perindopril, enalapril, lisinopril) cause a dry, tickling cough in 5–35% of users, and this is a class effect. It typically starts within weeks of initiating the medication but can develop months or years later. The cough is often worse at night and does not produce sputum. Importantly, it resolves within 1–4 weeks of stopping the ACE inhibitor (sometimes up to 12 weeks). Switching to an ARB (candesartan, irbesartan, telmisartan) provides equivalent blood pressure and heart protection without causing cough. This is always the first step to check in any person on an ACE inhibitor with a new cough.
Why might my cough be caused by reflux if I don't have heartburn?

Gastro-oesophageal reflux can cause cough even when there is no burning or heartburn — this is sometimes called laryngopharyngeal reflux or 'silent reflux.' Tiny amounts of stomach acid or non-acid material reach the back of the throat, triggering the cough reflex without causing the typical heartburn sensation. Clues include a cough that worsens when lying flat, after meals, or after alcohol; a persistent throat-clearing sensation; hoarseness in the mornings; or a bitter taste. Treatment includes twice-daily PPI for 8–12 weeks alongside lifestyle measures — weight loss, head-of-bed elevation, avoiding meals within 3 hours of sleep.
What is refractory chronic cough and how is it treated?

Refractory chronic cough (RCC) is diagnosed when cough persists despite thorough investigation and adequate treatment of all identified causes. The emerging understanding is that RCC often reflects cough hypersensitivity syndrome — increased sensitivity of the laryngeal cough reflex to normal stimuli like cold air, talking, or perfume. Treatment has two main arms. Speech pathology cough suppression therapy — a structured program teaching laryngeal control techniques — has randomised trial evidence showing approximately 40% reduction in cough frequency and is recommended by the European Respiratory Society. For persistent cough, neuromodulators including gabapentin and low-dose morphine (off-label) provide additional benefit.
When does chronic cough need urgent investigation for cancer?

A smoking history is the most important risk factor for lung cancer presenting as cough. Any current or ex-smoker aged 45 or over with a new or changed cough should have a chest X-ray arranged promptly; if normal and symptoms persist, CT chest is the next step. Other red flags warranting urgent investigation regardless of smoking status include: coughing up blood (haemoptysis, even small amounts), unexplained weight loss, hoarseness lasting more than three weeks, difficulty swallowing, unexplained fatigue or fevers, and palpable lymphadenopathy. Eligible ex- and current smokers aged 50–70 with 30 or more pack-years of smoking history can access the Lung Cancer Screening Program for biennial low-dose CT.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.