Bronchitis is inflammation and irritation of the airways (bronchial tubes) of the lungs. Coughing is the main symptom. Other symptoms can include mucus (sputum) when coughing, fever, and mild wheezing.

Bronchitis is usually caused by infection from a virus (less commonly with bacteria or a fungus). It can also develop after exposure to chemicals or air pollution, including tobacco smoke.

There are two types of bronchitis.

• Acute bronchitis develops suddenly. It generally lasts less than 2 to 3 weeks. Most healthy people who develop bronchitis get better without any complications.
• Chronic bronchitis recurs and becomes long-term (chronic), especially in people who smoke. A cough that produces too much sputum and is present most days during a 3-month period for at least 2 years in a row suggests chronic bronchitis. Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD).