Bronchitis (bron-KI-tis) is a condition in which the bronchial tubes become inflamed. These tubes carry air to your lungs. (For more information about the bronchial tubes and airways, go to the Diseases and Conditions Index How the Lungs Work article.)
People who have bronchitis often have a cough that brings up mucus. Mucus is a slimy substance made by the lining of the bronchial tubes. Bronchitis also may cause wheezing (a whistling or squeaky sound when you breathe), chest pain or discomfort, a low fever, and shortness of breath.
Figure A shows the location of the lungs and bronchial tubes in the body. Figure B is an enlarged, detailed view of a normal bronchial tube. Figure C is an enlarged, detailed view of a bronchial tube with bronchitis. The tube is inflamed and contains more mucus than usual.
The two main types of bronchitis are acute (short term) and chronic (ongoing).
Infections or lung irritants cause acute bronchitis. The same viruses that cause colds and the flu are the most common cause of acute bronchitis. These viruses are spread through the air when people cough. They also are spread through physical contact (for example, on hands that have not been washed).
Sometimes bacteria cause acute bronchitis.
Acute bronchitis lasts from a few days to 10 days. However, coughing may last for several weeks after the infection is gone.
Several factors increase your risk for acute bronchitis. Examples include exposure to tobacco smoke (including secondhand smoke), dust, fumes, vapors, and air pollution. Avoiding these lung irritants as much as possible can help lower your risk for acute bronchitis.
Most cases of acute bronchitis go away within a few days. If you think you have acute bronchitis, see your doctor. He or she will want to rule out other, more serious health conditions that require medical care.
Chronic bronchitis is an ongoing, serious condition. It occurs if the lining of the bronchial tubes is constantly irritated and inflamed, causing a long-term cough with mucus. Smoking is the main cause of chronic bronchitis.
Viruses or bacteria can easily infect the irritated bronchial tubes. If this happens, the condition worsens and lasts longer. As a result, people who have chronic bronchitis have periods when symptoms get much worse than usual.
Chronic bronchitis is a serious, long-term medical condition. Early diagnosis and treatment, combined with quitting smoking and avoiding secondhand smoke, can improve quality of life. The chance of complete recovery is low for people who have severe chronic bronchitis.