Definition of Bronchitis:

Bronchitis is an inflammation of the main air passages to the lungs. Bronchitis may be short-lived (acute) or chronic, meaning that it lasts a long time and often recurs.

See also: Chronic obstructive pulmonary disease (COPD)

Causes, incidence, and risk factors:

Acute bronchitis generally follows a viral respiratory infection. At first, it affects your nose, sinuses, and throat and then spreads to the lungs. Sometimes, you may get another (secondary) bacterial infection in the airways.This means that bacteria infect the airways, in addition to the virus.

People at risk for acute bronchitis include:

• Elderly, infants, and young children
• Persons with heart or lung disease
• Smokers

Chronic bronchitis is a long-term condition. People have a cough that produces excessive mucus. To be diagnosed with chronic bronchitis, you must have a cough with mucus most days of the month for at least 3 months.

Chronic bronchitis is also known as chronic obstructive pulmonary disease, or COPD for short. (Emphysema is another type of COPD.) As the condition gets worse, you become increasingly short of breath, have difficulty walking or exerting yourself physically, and may need supplemental oxygen on a regular basis.

Cigarette smoke, including long-term exposure to second-hand smoke, is the main cause of chronic bronchitis. The severity of the disease often relates to how much you smoked or how long you were exposed to the smoke.

The following things can make bronchitis worse:

• Air pollution
• Allergies
• Certain occupations (such as coal mining, textile manufacturing, or grain handling)
• Infections