Croup is swelling in the voice box and wind pipe. The swelling can make it hard to breathe. It can also cause a barking cough.

Upper Respiratory System in a Child
Nucleus factsheet image
Copyright © Nucleus Medical Media, Inc.


Croup is caused by viral infections such as:

  • Parainfluenza
  • Influenza virus type A and B
  • Adenovirus
  • Respiratory syncytial virus
  • Enterovirus
  • Rhinovirus
  • Coronavirus
  • Echovirus
  • Human bocavirus

Risk Factors

Croup is most common in children between 6 months and 3 years of age. This is because young children have a smaller airway. Croup is also more common in the fall and early winter months.

Other things that may raise the risk are:

  • Having an upper respiratory infection
  • Poor immunization, especially against diphtheria



The first symptoms may be like a common cold. They often happen at night. Croup symptoms may be:

  • Cough spasms
  • A cough that sounds like a barking seal
  • Hoarseness
  • Fever
  • Problems breathing
  • A harsh, high-pitched sound when your child breathes in, especially when crying or upset
  • Drooling and problems swallowing
  • Decreased alertness
  • Bluish color of nails, lips, or around the mouth


You will be asked about your child's symptoms and health history. A physical exam will be done. This is often enough to make the diagnosis.



The infection often goes away in a week. The goal of treatment is supportive care while the child heals. This may include things like fluids and warm, moist air to help with breathing.

Children with severe symptoms may need a breathing tube placed in the throat to help open the airway. This is not common.


Medicine may be needed to manage symptoms. The ones given depend on whether croup is mild or severe. They may be:

  • Over-the-counter medicine to lower fever and ease discomfort
  • Steroids to reduce swelling in the airways
  • Epinephrine to ease swelling until steroids start to work
  • Oxygen therapy for severe breathing problems


The risk of croup can be lowered by washing hands often and making sure a child's vaccines are up to date.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (Laryngotracheobronchitis)


Healthy Children—American Academy of Pediatrics 

Kids Health—Nemours Foundation 


About Kids Health—The Hospital for Sick Children 

Health Canada 


Croup. EBSCO DynaMed website. Available at: . Updated December 12, 2019. Accessed January 9, 2020.

Croup. Family Doctor—American Academy of Family Physicians. website. Available at: Updated March 20, 2017. Accessed January 9, 2020.

Smith DK, McDermott AJ, et al. Croup: Diagnosis and Management. Am Fam Physician. 2018 May 1;97(9):575-580.

What is croup and how is it treated? Healthy Children—American Academy of Pediatrics website. Available at: Updated November 21, 2015. Accessed January 9, 2020.