Chronic Bronchitis: Definition, Symptoms, Causes, and Evidence-Based Management

Definition (GOLD/ATS)

Productive cough ≥3 months/year for ≥2 consecutive years, not explained by other lung disease. A phenotype of COPD.

Clinical Presentation

• Chronic cough + sputum (mucoid → purulent with exacerbations).
• Progressive dyspnea (initially exertional, later at rest).
• Wheezing, chest tightness, fatigue.
• Frequent lower respiratory infections.

Risk Factors

• Smoking: #1 cause (90% of cases); dose-response relationship.
• Occupational dusts/fumes (silica, cadmium, welding, grain).
• Indoor biomass smoke (global burden).
• Air pollution (PM2.5, NO2).
• Genetic: α1-antitrypsin deficiency (rare).
• Childhood respiratory infections, low birth weight (impaired lung growth).

Diagnostic Evaluation

• Spirometry: Post-bronchodilator FEV1/FVC <0.70 confirms airflow limitation.
• Chest CT: Bronchial wall thickening, mucus plugging, emphysema.
• Sputum culture during exacerbations guides antibiotics.

Management (GOLD 2024)

Domain	Interventions
Smoking Cessation	Varenicline, bupropion, NRT + counseling—single most effective intervention
Bronchodilators	LAMA (tiotropium) ± LABA (formoterol, salmeterol) — first-line maintenance
Inhaled Corticosteroids	Add if eosinophils ≥300/µL or frequent exacerbations; triple therapy (ICS/LAMA/LABA)
Pulmonary Rehab	Exercise + education → ↑ exercise capacity, ↓ dyspnea, ↓ hospitalizations
Vaccines	Annual influenza, pneumococcal (PCV20 or PPSV23), COVID, RSV (older adults)
Exacerbation Plan	Action plan: increase bronchodilators, add prednisone 40 mg × 5d, antibiotics if purulent sputum
Advanced	Roflumilast (chronic bronchitis phenotype, FEV1<50%), azithromycin maintenance, lung volume reduction, transplant

Prognosis

FEV1 decline ~30–60 mL/yr (vs. 20–30 mL normal). Early cessation slows decline. BODE index (BMI, Obstruction, Dyspnea, Exercise) predicts mortality.