What Causes Acute Bronchitis?

Acute bronchitis is usually caused by a virus. It is more common during the winter months and often develops after an upper respiratory illness such as influenza (flu) or a cold caused by a virus such as coronavirus, adenovirus, or a rhinovirus.
Acute bronchitis can also be caused by exposure to smoke, chemicals, or air pollution, all of which can irritate the bronchial tubes. It can also develop from accidentally inhaling food or vomit.

Drinking plenty of fluid will keep the patient well hydrated and hydration keeps secretions into the bronchial tubes more liquid and easier to expel.