Bronchitis vs. Asthma: Differences, Severity, and Management

Both affect airways and cause cough/shortness of breath, but they are distinct diseases with different pathophysiology, chronicity, and treatment.

Bronchitis

Acute Bronchitis: Viral (90%) or bacterial inflammation of bronchial tubes. Self-limited (1–3 weeks). Cough (productive), low-grade fever, malaise. Antibiotics rarely needed. Supportive care.

Chronic Bronchitis: Productive cough ≥3 months/year for 2 consecutive years. COPD phenotype. Caused by smoking, air pollution. Fixed airflow obstruction. Managed with bronchodilators, smoking cessation, pulmonary rehab.

Asthma

Chronic inflammatory airway disease with variable airflow obstruction, bronchial hyperresponsiveness. Symptoms: wheeze, cough, chest tightness, dyspnea—episodic and reversible. Triggers: allergens, exercise, cold air, viruses, irritants. Onset often childhood, but can start any age.

Key Differences

Feature	Bronchitis (Acute)	Chronic Bronchitis (COPD)	Asthma
Inflammation	Acute, neutrophilic	Chronic, neutrophilic/macrophage	Chronic, eosinophilic/Th2
Airflow Obstruction	Transient, reversible	Fixed, poorly reversible	Variable, largely reversible
Cough	Acute, productive	Chronic, productive	Intermittent, dry or productive
Wheeze	Sometimes	Common	Hallmark
Sputum	Mucoid/purulent	Chronic mucoid	Often scant, thick plugs
Triggers	Infection	Smoking, pollution	Allergens, exercise, cold, stress
Response to Bronchodilators	Modest	Modest	Marked (>12% FEV₁)
Primary Treatment	Supportive	LAMA/LABA, quit smoking	ICS ± LABA, biologics

Severity & Overlap

Both can be life-threatening: acute bronchitis → pneumonia; asthma → status asthmaticus; COPD exacerbation → respiratory failure. Asthma-COPD Overlap (ACOS) exists—features of both. Requires specialist management.

See a clinician for persistent cough, wheeze, or dyspnea. Spirometry pre/post bronchodilator confirms diagnosis.