Chronic cough
Chronic cough, defined as cough lasting more than 8 weeks, is most often caused by upper airway cough syndrome, asthma, gastroesophageal reflux disease (GERD), nonasthmatic eosinophilic bronchitis, smoking, or ACE inhibitor use, frequently in combination. Evaluation is a stepwise sequence of history, examination, and chest radiography followed by sequential empiric treatment trials, reserving cross-sectional imaging and bronchoscopy for red flags or treatment failure.
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What this article covers
- Overview
Chronic cough is cough lasting more than 8 weeks, distinguished from acute cough (under 3 weeks) and subacute cough (3-8 weeks, usually postinfectious).
- Epidemiology
One of the most common reasons for ambulatory referral to primary care and pulmonology.
- Risk factors
Active cigarette smoking, the leading reversible risk factor and a direct cause independent of COPD.
- Pathophysiology
UACS (formerly postnasal drip syndrome): rhinitis or sinusitis produces posterior nasal secretions that stimulate pharyngeal and laryngeal cough receptors.
- Clinical features
The defining feature is cough duration greater than 8 weeks; the character of the cough (dry versus productive, timing) does not reliably predict the underlying cause.
- Differential diagnosis
Lung cancer, the most dangerous cause to miss: weight loss, hemoptysis, or a heavy smoking history rule this in over benign causes; excluded by a normal chest radiograph/CT with no mass or nodule.
- Diagnosis
Chronic cough is defined by duration alone (more than 8 weeks) and diagnosed by working through the CHEST expert cough panel's stepwise algorithm, which establishes the underlying cause(s) through…
- Management
Discontinue every reversible contributor at the first visit: stop the ACE inhibitor (switch to an angiotensin receptor blocker if renin-angiotensin blockade is still needed) and counsel and support…
- Complications
Missed or delayed diagnosis of lung cancer or tuberculosis, the most serious consequence of symptomatic treatment without red-flag evaluation.
- Prognosis
Cause-directed therapy resolves most chronic cough once the correct cause (UACS, asthma, GERD, ACE inhibitor) is identified and treated or the offending drug is stopped.
- Prevention
Avoid ACE inhibitors in patients with a prior history of ACE inhibitor cough; use an angiotensin receptor blocker instead when renin-angiotensin system blockade is indicated.
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Related articles
- Upper airway cough syndrome
Upper airway cough syndrome, formerly called postnasal drip syndrome, is chronic cough driven by postnasal drainage from allergic rhinitis, nonallergic rhinitis, or chronic sinusitis, and is one of the three most common causes of chronic cough alongside GERD and asthma. It is diagnosed clinically and confirmed by response to an empiric trial of therapy directed at the underlying rhinitis or sinusitis subtype.
- Asthma
Asthma is a chronic inflammatory airway disorder causing episodic, reversible airflow obstruction confirmed by spirometry or bronchial challenge testing. Management is a stepwise ladder led by inhaled glucocorticoids plus as-needed SABA or ICS-formoterol, escalating to biologics for severe type 2-high disease, with an oral glucocorticoid burst and frequent SABA for exacerbations.
- Gastroesophageal reflux disease (GERD)
GERD is retrograde reflux of gastric contents into the esophagus causing heartburn and regurgitation, diagnosed clinically and confirmed by response to an empiric PPI trial, with endoscopy reserved for alarm features or refractory symptoms. Management proceeds from lifestyle measures through an 8-week once-daily PPI trial, dose escalation or agent switch for partial response, and fundoplication for medication-refractory or regurgitation-predominant disease.
- Chronic obstructive pulmonary disease (COPD)
Chronic obstructive pulmonary disease is a persistent, usually progressive airflow obstruction driven mainly by cigarette smoke, confirmed by a postbronchodilator FEV1/forced vital capacity (FVC) ratio below 0.70 and staged by GOLD spirometric grade plus symptom/exacerbation group. Maintenance management is a stepwise ladder of smoking cessation, long-acting bronchodilators, add-on inhaled glucocorticoid, roflumilast, or azithromycin for frequent exacerbators, long-term oxygen for resting hypoxemia, and vaccination, with acute exacerbations managed as a separate protocol.
- Bronchiectasis
Bronchiectasis is chronic, irreversible bronchial dilation from a cycle of infection, inflammation, and airway destruction, diagnosed by high-resolution CT and managed with airway clearance, treatment of the underlying cause, and antibiotics for exacerbations.
- Lung cancer
Lung cancer is the leading cause of cancer death worldwide, split into non-small cell lung cancer (NSCLC, 80% of cases: adenocarcinoma, squamous cell, large cell) and small cell lung cancer (SCLC, 10-15%), both driven overwhelmingly by cigarette smoking. Diagnosis requires tissue histopathology, staging drives treatment (TNM staging for NSCLC, limited versus extensive stage for SCLC), and management ranges from lobectomy in early-stage disease through concurrent chemoradiation and consolidation immunotherapy in locally advanced disease to targeted tyrosine kinase inhibitors, immune checkpoint inhibitors, or platinum-based chemotherapy in metastatic disease.
- Tuberculosis
Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading global cause of infectious death and presents as latent infection, primary/secondary pulmonary disease, or extrapulmonary and disseminated (miliary) disease. Diagnosis rests on AFB smear, NAAT, and mycobacterial culture (the gold standard), and drug-susceptible active disease is treated with a four-drug regimen (isoniazid, rifampin, pyrazinamide, ethambutol) for 2 months followed by isoniazid plus rifampin for 4 to 7 months.
- Allergic rhinitis
Allergic rhinitis is an IgE-mediated inflammation of the nasal mucosa causing sneezing, rhinorrhea, congestion, and itch on allergen exposure, classified as seasonal or perennial. Diagnosis is clinical, supported by skin or specific IgE testing to identify allergens, and treatment is allergen avoidance with intranasal corticosteroids first-line, escalating to combination therapy and allergen immunotherapy.
- Bordetella pertussis (whooping cough)
Whooping cough is a highly infectious bronchitis caused by the gram-negative coccobacillus Bordetella pertussis, marked by catarrhal, paroxysmal, and convalescent stages with lymphocytosis; diagnosis is clinical, confirmed by nasopharyngeal PCR, and treated with azithromycin plus prophylaxis of close contacts.