What Is Croup?

Signs and symptoms of croup and how to treat it

An Asian mother comforts her baby that is experiencing symptoms of croup, a common childhood viral infection that affects the upper airway.

Signs and symptoms of croup and how to treat it

Croup is a common childhood viral infection that affects the upper airway. It often begins as a respiratory infection, such as a cold, and typically affects children between 6 months and 3 years of age. 


One of the most distinctive signs and symptoms of croup is a loud barking cough. Despite the scary-sounding cough, most cases of croup are not serious and can be treated at home. Read on to learn what to expect if your child becomes sick with croup. 

Croup signs and symptoms

The harsh, barking cough that is a hallmark of croup is due to swelling of the child’s voice box, or larynx, says Tina Chu, MD, a pediatrician at Scripps Coastal Medical Center in San Marcos.


“When a child with croup coughs, air forced through the narrowed airway causes the swollen vocal cords to create a barking sound,” says Dr. Chu. “Inhaling may produce a high-pitched whistling sound called stridor.”


Along with the cough and stridor, symptoms of croup can include a hoarse voice, heavy or noisy breathing and fever. The barking cough is often worse at night; a child may go a full day without coughing only to start again at bedtime. 


Croup symptoms generally last three to five days. You should call your pediatrician about croup if your child has severe symptoms or doesn’t improve after five days. Croup is rarely serious, but take your child to the emergency department or urgent care immediately if they have any of these symptoms:


  • Noisy, high-pitched sounds when both inhaling and exhaling sounds
  • Fast breathing
  • Difficulty breathing
  • Blue or grayish skin around the nose, mouth or fingernails 
  • Drooling or difficulty swallowing
  • Severe anxiety or agitation
  • Fatigue or lethargy

Treatment for croup

Home treatment of croup is appropriate for most cases. Because crying and anxiety can make breathing more difficult, try to keep your child calm and comfortable. Here are a few suggestions:


  • In a soothing voice, reassure your child that the cough sounds worse than it is, and they are OK. 
  • Help them focus on something else with a quiet activity like a story, movie or drawing.
  • Humid air may help some children breathe more easily. Use a humidifier or run a hot shower and let steam fill the bathroom. For other kids, cool moist air from a vaporizer may help soothe irritated airways. Try both and see which works better for your child.
  • Have them sit upright in your lap, bed or a comfortable chair, which can help ease breathing. 
  • Encourage your child to rest as much as possible.
  • If your child is running a fever, over-the-counter medications such as Tylenol can help lower their temperature. Do not give children aspirin, as this raises the risk of a rare but serious condition called Reye’s syndrome.
  • Over-the-counter cough medicine will not help croup and may be harmful to young kids.


If your child still has symptoms after five days of home croup treatment, call your pediatrician. They may prescribe a steroid medicine to help reduce inflammation in the airway; usually, a single dose will take effect in a few hours and last for 24 hours. 


“More serious breathing problems may require inhaled epinephrine, which provides relief immediately but wears off quickly,” says Dr. Chu. “We will want to keep your child in the emergency department for several hours after an epinephrine treatment to make sure they’re breathing well, and it is safe to go home.”


In very severe cases of croup, your child may be admitted to the hospital for treatment and monitoring; however, this is not common.

Preventing croup

Croup often begins as a common cold, so take the same steps to prevent it as you would with a respiratory infection. This means making sure your child frequently washes their hands with soap and water, eats a healthy diet, gets plenty of rest and avoids contact with others who are sick.