Acute vs. Chronic Bronchitis: Differences in Duration, Causes, and Symptoms

Feature	Acute Bronchitis	Chronic Bronchitis
Duration	Days to 3 weeks	≥3 months/year for 2+ consecutive years (COPD definition)
Cause	Viruses (90%+): influenza, RSV, rhinovirus; rarely bacteria	Cigarette smoking (primary); air pollution, occupational dusts/chemicals
Pathology	Transient bronchial inflammation	Chronic mucus hypersecretion, goblet cell hyperplasia, airway remodeling
Cough	Acute, often productive; resolves	Persistent, productive ("smoker's cough")
Other symptoms	Fever, malaise, wheeze, chest tightness	Dyspnea on exertion, frequent exacerbations, reduced exercise tolerance
Treatment	Supportive: fluids, rest, honey, bronchodilators if wheezing; antibiotics rarely needed	Smoking cessation (key), bronchodilators, inhaled corticosteroids, pulmonary rehab, vaccinations

Chronic bronchitis is a phenotype of COPD; acute bronchitis is a self-limited infection.