Clinical Definition

Bronchitis is inflammation of the main bronchial tubes leading to the lungs. In some instances, there may also be tracheal involvement. The condition can develop acutely from infectious agents like the parainfluenza virus, or occur chronically from bronchial epithelial injury due to lung irritants like cigarette smoking.

In Our Own Words

Bronchitis, when it’s acute or short term, is often due to a virus. The two airway tubes connected to the trachea, which branch off into the left and right lung, are called the bronchi. Viruses can infect the cells that make up the airway lining, and bronchitis occurs when the walls or lining of these tubes become red, swollen and inflamed, often leading to a cough that brings up mucus.

Chronic bronchitis, which can last for months, may also be due to viruses, but is most often caused by exposure to an irritant, like cigarette smoke. One additional cause of bronchitis, which may be surprising, is GERD.