Croup features a cough that sounds like a seal barking. Most children have what appears to be a mild cold for several days before the barking cough becomes evident. As the cough gets more frequent, the child may have labored breathing or stridor (a harsh, crowing noise made during inspiration).

Croup is typically much worse at night. It often lasts 5 or 6 nights, but the first night or two are usually the most severe. Rarely, croup can last for weeks. Croup that lasts longer than a week or recurs frequently should be discussed with your doctor to determine the cause.

Children with croup are usually diagnosed based on the parent's description of the symptoms and a physical exam. Sometimes a doctor will even identify croup by listening to a child cough over the phone. Occasionally other studies, such as x-rays, are needed.

A physical examination may show chest retractions with breathing. Listening to the chest through a stethoscope may reveal prolonged inspiration or expiration, wheezing, and decreased breath sounds.

An examination of the throat may reveal a red epiglottis. A neck x-ray may reveal a foreign object or narrowing of the trachea.