Am Fam Physician. 1998;57(6):1281-1282
See related article on acute bronchitis.
What is acute bronchitis?
Acute bronchitis is an infection of the bronchial tree (tubes that carry air from the mouth and nose to the lungs). When these tubes get infected, they swell, and mucus forms. Mucus is the material that comes up when you cough. The swelling of the tubes makes it more difficult for you to breathe. It may make you wheeze when you breathe.
What causes acute bronchitis?
Acute bronchitis is almost always caused by viruses that get into the bronchial tree. The same viruses that cause colds in the nose and throat can cause acute bronchitis.
Viruses attack the lining of the bronchial tree, causing damage. As your body fights back against these viruses, more swelling occurs and more mucus is made. Even though your body kills off the viruses, it takes time for your body to repair the damage caused by the infection. During this time, you may continue to cough and wheeze. Anything that causes further damage to the bronchial tree, such as cigarette smoking, will lengthen the time it takes for you to get better.
How do people get acute bronchitis?
Acute bronchitis is spread from person to person by coughing. The viruses that cause the infection are sprayed into the air or onto people's hands when they cough. You can catch acute bronchitis if you breathe in the viruses or touch hands coated with these viruses.
You are more likely to get acute bronchitis if your bronchial tree is already damaged. Cigarette smoking or being around damaging fumes (such as industrial fumes) can break down your body's defense against infection. People who smoke are more likely to get acute bronchitis and to have it longer. If you stop smoking, you are less likely to get acute bronchitis in the future.
What tests can tell my doctor if I have acute bronchitis?
There are no tests to prove that you have acute bronchitis. However, you may need to have some tests to make sure that you don't have something else, like pneumonia. Your doctor may have you get a chest x-ray or take a breathing test (called spirometry) to check for pneumonia or other lung problems.
How is acute bronchitis treated?
Acute bronchitis is caused by viruses, so antibiotics (medicines that kill bacteria) are not helpful. Even when the mucus you cough up is colored or thick, antibiotics probably won't help you get better any faster.
For some people with acute bronchitis, doctors prescribe medicines that are used to treat asthma. These medicines help open the bronchial tubes and clear out the mucus. The asthma medicines used for acute bronchitis are usually given in an inhaler. An inhaler sprays the medicine right into the bronchial tree, where it is most useful.
If you smoke you should cut down on the number of cigarettes you smoke, or stop smoking altogether. This will help limit the damage to your bronchial tree. You will heal faster if you are not smoking. You should also avoid breathing fumes or chemicals that can damage your lungs, such as smoke or industrial fumes.
What special problems can occur with acute bronchitis?
Sometimes the cough from acute bronchitis lasts for several weeks. The cough can even drag on for months. Usually this happens because the bronchial tubes are taking a long time to heal. However, the cough may also be a sign of other problems.
Acute bronchitis can be confused with asthma. If you continue to wheeze and cough, especially at night or when you are active, you could have mild asthma. If your cough and wheezing problems drag on, your doctor may want you to take some breathing tests to check for asthma.
Pneumonia and acute bronchitis can sometimes cause similar symptoms. If you have a high fever, feel very sick and weak, and continue to cough, you should call your doctor. You may need to have a chest x-ray to check for pneumonia.
Bronchitis can also be caused by acid coming up from the stomach and dripping into the lungs when you sleep. If your cough continues and you sometimes have a bad-tasting fluid come up into your mouth, you should see your doctor. Medicines can reduce the acid in your stomach, which may help your cough go away.
When should I see my doctor?
If your cough lasts more than one month or if you keep having a fever, you should see your doctor. You should also see your doctor if you cough up blood. If you have trouble breathing only when you lie down, or if your feet swell, you need to see your doctor.
How can I keep from getting acute bronchitis again?
The best defense against acute bronchitis is not to smoke. Smoking damages the bronchial tree and makes it easier for viruses to cause infection. Smoking also slows down the healing time, so that it takes longer to get well.