Bronchitis Causes

Bronchitis is inflammation of the bronchi - the air tubes that carry air into your lungs. When they swell and fill with mucus, you cough. The causes split cleanly by whether the illness is short-lived (acute) or long-running (chronic).

Acute bronchitis: almost always a virus

• Viruses: the same ones behind colds and flu (rhinovirus, influenza, coronaviruses, RSV) cause about 9 in 10 cases. It typically follows a cold - the infection moves from nose and throat down into the airways
• Bacteria: a small minority (such as Bordetella pertussis - whooping cough - or Mycoplasma). This is why antibiotics routinely fail acute bronchitis: you cannot kill a virus with them
• Irritants that tip you over: smoke, dust, air pollution, chemical fumes - they inflame the airway lining and give viruses an easier entry
• What makes it more likely: winter season, crowded exposure, smoking, asthma, reflux, and a run-down immune system

Chronic bronchitis: the smoker's disease, mostly

Chronic bronchitis - a daily productive cough for at least 3 months a year, 2 years running - is one half of COPD (chronic obstructive pulmonary disease). Its causes:

• Smoking: the overwhelming cause - tobacco smoke paralyzes the cilia (the airway's cleaning hairs) and keeps the tubes inflamed and mucus-logged
• Biomass fuel smoke: in India, years of cooking over wood, dung or crop-residue fires in poorly ventilated kitchens is a major cause, especially in women who never smoked
• Air pollution and occupational dust: coal, cement, textile, mining dust; city air adds to the load
• Repeated acute infections: each bout can leave airways a little more reactive

The classical view

The classics described Kasa (cough disorders) arising from aggravated Vata and Kapha obstructing the chest's channels, with causes that read remarkably modern: smoke (dhuma), dust (raja), dry and cold food, suppression of natural urges, and seasonal transitions. Madhava Nidana's Kasa chapter lists the same irritant-driven picture. The old observation holds: what you breathe day after day writes itself into your airways.

One-line summary

Acute bronchitis is a virus doing a short visit; chronic bronchitis is years of smoke (tobacco or cooking fire) doing slow damage. The fix differs accordingly: patience for the first, removal of the smoke for the second.