Acute bronchitis is usually caused by a viral infection. This is most often the same viruses that cause colds and the flu. It may also be caused by a bacterial infection, or by physical or chemical agents that are breathed in.

What is the most common cause of bronchitis?

The most important cause of chronic bronchitis is cigarette smoking. Air pollution and your work environment may also play a role. This condition causes a cough that's often called smoker's cough. It also causes you to cough up mucus, wheeze, and have chest discomfort.

Can you get bronchitis out of nowhere?

Acute bronchitis comes on suddenly. It causes the tubes that carry air to your lungs to swell. It usually gets better on its own without the need for medication. The infection usually lasts for 3 to 10 days, but the cough can continue for several weeks.