The Facts

If your child has a harsh and barking cough (which sounds a bit like a seal), hoarseness, runny nose, and a mild fever, he or she may have a condition called croup.

Croup is a problem that affects most children during early childhood. It is caused by a viral infection that causes swelling in the trachea (windpipe) and larynx (voice box). Croup is most common in children under the age of 5 years, and especially those under 3 years old.

More boys than girls are affected by croup. Croup can be scary for children and parents, but it's not usually serious.


Croup is caused by a number of different types of viruses. The most common cause is the parainfluenza virus. Viruses that cause the common cold and flu, and occasionally bacteria, can also cause croup. Croup may occur anytime during the year, but children most often catch it in the fall or winter.

The viruses that cause croup are spread from one child to another by coughing and sneezing. The viruses can also be spread among children by their hands, shared toys, and shared drinking glasses or spoons and forks. Children with croup are most contagious during the first few days of their illness.

Symptoms and Complications

The symptoms of croup are caused by swelling in the trachea and larynx that has been infected by a virus. The swelling causes the upper airways to narrow, resulting in stridor (a harsh, loud, high-pitched noise when your child takes a breath) and a barking cough.

Children with croup often have a mild fever and runny nose before the onset of the stridor and barking cough. Croup symptoms are usually worse at night. Your child's croup symptoms will likely get better on their own in 3 to 5 days, but may last for up to one week. Some children may have a mild cough for a few days after the main symptoms are over.

Some children will have more severe symptoms of croup than others, and symptoms are usually more severe in children 3 years of age and younger. Most children have mild symptoms, which include an occasional barking cough (the typical croup cough), little if any stridor when resting, and little if any indrawing of the chest wall.

More severe croup may be associated with stridor, fast or difficult breathing, flaring nostrils, unusual restlessness, and chest wall retractions (the child's chest muscles are sucked in).

You should call your doctor if your child:

  • starts drooling or has trouble swallowing
  • has blue lips and fingernails
  • becomes restless or confused
  • does not sound better after moist air treatment or going outdoors
  • has increasing trouble breathing

Making the Diagnosis

If your child has the typical signs and symptoms of croup, your doctor will make a diagnosis after listening to the chest with a stethoscope. Occasionally an X-ray may need to be taken to help make the diagnosis.

Your doctor may tell you that your child has either a mild, moderate, or severe case of croup depending on the severity of the symptoms. About 5% of children who get croup need to be admitted to the emergency room or stay overnight in the hospital for treatment.

Treatment and Prevention

The best way to prevent croup is to keep your children away from others who have symptoms of the condition. Unfortunately, this isn't always practical or possible. However, it will help if everyone in the home, and school or daycare washes their hands often and throws away tissues used for runny noses and sneezes right away. Anyone with a cough or cold should be asked to avoid kissing or playing with your child.

Cases of mild-to-moderate croup can be treated at home. Since crying makes symptoms worse, keeping your child comfortable and happy will help. In addition, encourage your child to drink plenty of fluids and ensure they get as much rest as possible.

Although several recent studies have not shown a clear benefit from using mist or humidity for children with croup in the emergency department, this is still recommended for the management of croup at home. If your child has stridor, a humidifier may help him or her breathe more easily. A cool mist vaporizer or warm moist air may both be effective. Sitting with your child in a bathroom filled with hot shower steam for 10 to 20 minutes often helps. Taking your child outside into the cool air for about 10 minutes may also help.

Like the common cold, we haven't found a way to kill the viruses that cause croup. If your child has a fever or chest discomfort, you can give them acetaminophen* or ibuprofen.

Cough medications have not been found to be of any benefit for children with croup. Because antibiotics do not kill viruses, your doctor will not prescribe them unless another infection (such as an associated ear infection) potentially caused by bacteria is suspected. A single dose of an oral cortisone medication may be prescribed by your doctor to reduce the swelling in your child's trachea.

The first 3 nights of croup are always the worst, after which symptoms will begin to abate.

If your child is one of the few that has severe croup and requires hospitalization, he or she will be given inhaled medication and oral or intravenous (IV) cortisone medication to relieve the airway inflammation and to open up the breathing passages.

*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.