Bronchitis is inflammation and irritation of the airways (bronchial tubes) of the lungs. Symptoms include a persistent cough that often produces mucus (sputum), fever, mild wheezing, and chest pain.

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 form of chronic obstructive pulmonary disease (COPD).