Bronchitis means that the tubes that carry air to the lungs (the bronchial tubes) are inflamed and irritated. When this happens, the tubes swell and produce mucus. This makes you cough.

Acute bronchitis usually comes on quickly and gets better after 2 to 3 weeks. Most healthy people who get acute bronchitis get better without any problems. See a picture of acute bronchitis.  Both children and adults can get acute bronchitis.  WedMD