A stuffy or congested nose occurs when the tissues lining the nose become
swollen. The swelling is due to inflamed blood vessels. The problem may also
include nasal discharge or "runny nose." If excess mucus runs down the back of
your throat, it may cause a cough or sore throat. A runny nose may be annoying
and uncomfortable, but it usually clears up on its own. Occasionally, it can be
a sign of a more severe problem. A runny nose may be severe in infants.