Acute Bronchitis | Causes & Risk Factors


What causes acute bronchitis?

Acute bronchitis is almost always caused by viruses that attack the lining of the bronchial tree and cause infection. As your body fights back against these viruses, more swelling occurs and more mucus is produced. It takes time for your body to kill the viruses and heal the damage to your bronchial tubes.

In most cases, the same viruses that cause colds cause acute bronchitis. Research has shown that bacterial infection is a much less common cause of bronchitis than doctors used to think. Very rarely, an infection caused by a fungus can cause acute bronchitis. Exposure to an irritant (such as smoke, dust or pollutants in the air) may cause bronchitis.

How do people get acute bronchitis?

The viruses that cause acute bronchitis are sprayed into the air or onto people’s hands when they cough. You can get acute bronchitis if you breathe in these viruses. You can also get it if you touch a hand that has the virus on it and then touch your eyes, nose or mouth.

If you smoke or are around damaging fumes (such as those in certain kinds of factories), you are more likely to get acute bronchitis and to have it longer. This is because your bronchial tree is already damaged. 

People who have gastroesophogeal reflux disease (GERD) can develop acute bronchitis when stomach acids get into the bronchial tree.

Written by editorial staff

Reviewed/Updated: 07/13
Created: 05/01