What is croup?
Croup is an infection usually caused by a virus. It causes the trachea (windpipe) and larynx (voice box) to swell, which results in the harsh "barking" cough. Croup usually lasts 5 to 6 days and is more common during the winter months and early spring.
Children who are 5 years old or younger are more likely to have croup. If your child was born prematurely, he or she is also at higher risk of getting croup.
Written by familydoctor.org editorial staff