What is acute bronchitis?
is an infection of the bronchial (say: brawn-kee-ull) tree. The bronchial tree is made up of the tubes that carry air into your lungs. When these tubes get infected, they swell and mucus (thick fluid) forms inside them. This makes it hard for you to breathe.
Acute bronchitis is bronchitis that lasts a short time (several weeks or less), while chronic bronchitis is bronchitis that is long-lasting or recurring (and is usually caused by constant irritation of the bronchial tree, such as from smoking).