Bronchitis is an infection that causes a cough. It happens when the tubes that carry air into the lungs, called the “bronchi,” get infected. Bronchitis usually oc­curs when a person gets a cold or the ...

Medically reviewed by Jurairat J. Molina, MD A chest X-ray cannot diagnose asthma but can provide valuable information during a severe attack or when someone is hospitalized with asthma complications.