What is croup?

Croup is a disease caused by a virus. It causes swelling in the airways and problems breathing. It is most common in children 3 months to 5 years old.


Common symptoms of croup can include:

  • cough that may sound like a seal’s bark
  • runny nose and congestion
  • laryngitis
  • fever
  • stridor, a high-pitched sound when your child breathes in

The symptoms often get worse at night and may wake your child from sleep.


Croup is usually diagnosed based on a physical examination. In some cases, your child’s doctor may order a chest x-ray to rule out other conditions.


Your child’s doctor may recommend home treatments to reduce symptoms. He or she may also prescribe medications to help reduce swelling in the airways. In severe cases, your child may need to be treated in the hospital.

Learn more about Pediatric Pulmonology, Allergy, Immunology and Sleep services at Boston Children’s Health Physicians.