But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit familydoctor.org , the AAFP patient education Web site. Bronchiolitis is a lung infection caused by a virus. Children under age two get this illness in the winter and the early spring.
Most children are sick about a week and then get well.
Your child will probably have a runny nose and a slight fever for two to three days. Then your child may begin to cough, breathe fast and wheeze for another two or three days. Your child is breathing very fast, more than 40 breaths in one minute. Your child has had heart disease or was born prematurely. In this case, call the doctor at the first signs of this illness.