What Is Croup?

Croup Symptoms, Diagnosis, and Treatment in Children

Croup is a common childhood viral infection of the larynx, trachea, and bronchial tubes that is easily recognized due to several distinctive characteristics. The highly contagious illness, also called laryngotracheobronchitis, is most prevalent in children between the ages of 6 months and 3 years but can affect children of all ages.

Symptoms, which often include a runny nose and a brassy cough, develop about two to six days after being exposed to someone with croup and typically self-resolve in two to five days. Cases are most common during the late fall, winter, and early spring, and around 3% of young children get croup each year.

Mother holding child sick with croup, lying together on a couch at home with fever and running nose
tatyana_tomsickova / Getty Images


One of the first tell-tale features of croup is the abrupt or sudden onset of symptoms. Children, who were well at bedtime, will often wake up in the middle of the night with a croupy cough and trouble breathing. The sound of the cough is also distinctive. Unlike other viral respiratory illnesses, which cause a dry, wet, or a deep cough, croup causes a unique cough that sounds like a barking seal.

A sign of moderate to severe croup is inspiratory stridor, which is a loud, high-pitched, harsh noise that children with croup often have when they are breathing in.

Stridor is often confused with wheezing, but unlike wheezing, which is usually caused by inflammation in the lungs, stridor is produced by inflammation in the larger airways.

Other common symptoms of croup include fever, hoarse throat, swollen lymph nodes, labored breathing, chest moving in and out more than normal while breathing, eye redness, and dehydration. A sore throat may be present when your child coughs. Many croup sufferers have decreased appetite and may avoid eating and drinking due to the persistent cough. Fevers are usually low grade but may rise up to 104 degrees.

Croup symptoms often follow a characteristic pattern. In addition to beginning in the middle of the night, symptoms are mostly better during the day, only to worsen again the next night. The barking cough usually subsides after two to three days but can last up to a week or so in more severe cases. Symptoms usually intensify when a child becomes anxious, upset, or agitated.


The symptoms of croup are caused by inflammation, swelling, and the buildup of mucus in the larynx, trachea (windpipe), and bronchial tubes. Since younger infants and children have smaller airways, this age group is most affected by croup. In contrast, older children will often just develop cold symptoms when they are infected by the same viruses.

It's estimated that around 75% of croup cases stem from human parainfluenza viruses (HPIVs). Rarely, cases of croup may come from bacterial infections, including bacterial tracheitis.

The vast majority of croup infections are caused by viruses. So, antibiotics, which only treat bacterial infections, won't help.


Because of the unique, tell-tale croup cough, the diagnosis is usually fairly easy to make. If a doctor hears a child cough, they can often tell if the child has croup while they are still in the waiting room or before the doctor enters the exam room. So, testing is usually not necessary.

Specifically, an x-ray is usually not required and only done to rule out other disorders, such as the ingestion of a foreign body. When an x-ray of the breathing tubes is done, it will usually show a characteristic "steeple sign," which shows a narrowing of the trachea.

The 17-Stage Scale

Doctors grade the severity of a child's croup on a 17-stage scale, assessing, among other symptoms, how much difficulty they are having breathing. The croup score is a standardized way to determine if a child has mild, moderate, or severe croup, which can help to dictate what treatments are necessary.

The croup score is based on a child's color (presence of cyanosis), the level of alertness, the degree of stridor, air movement, and degree of retractions while breathing, with zero points given if these findings are normal or not present, and up to three points given for more severe symptoms.

In general, children with a croup score of less than 4 have mild croup; 5 to 6 indicates mild/moderate croup; 7 to 8 points to moderate croup; and greater than 9 shows more severe croup.

Fortunately, the vast majority of children have mild croup and have no trouble breathing. Research shows that 85% of children taken to the emergency room with croup have mild cases, with only 1% to 8% of the cases severe enough to require hospital admission.

In some mild to moderate cases, children may have stridor when they are crying or agitated. Children with moderate or severe croup will have rapid breathing and retractions, which is a sign of increased difficulty in getting enough air. In more severe cases, children may also have stridor when they are resting.


Like most viral infections, there is no cure for croup. But there are many treatments that can help improve the symptoms and make your child feel better.

Mild croup symptoms can usually be safely treated at home. Common treatments include using humidified air, which can be delivered by a cool-mist humidifier. While studies have not shown humidified air to be an effective treatment for children with intense enough symptoms to be seen in a hospital setting, in mild cases, many families report steam temporarily alleviates their children's symptoms.

Using a hot steam vaporizer is usually discouraged because of the risk of your child getting burned if they touch the machine. Instead, warm steam can be delivered by turning on all of the hot water in the bathroom, including from the shower and sink, closing the bathroom door and holding your child as they breathe in the steamy, humidified air.

On cool nights, exposure to the cool nighttime air may also help symptoms. The cool air helps to reduce inflammation. To take advantage of this, it may help to bundle your child up and walk around outside for several minutes. It is probably not a good idea to keep their window open, at least not for long, as you don't want them to get too cold.

A well-known phenomenon of croup is that children often get better on the way to the emergency room—this is because cool air can help open up their airways.

Other treatments can include using a fever reducer (products containing acetaminophen or ibuprofen) and/or non-narcotic cough syrup (although they probably won't suppress the cough of croup) if your child is over 4 to 6 years old. Since symptoms worsen if your child is crying and agitated, trying to keep your child calm and distracted may also improve their symptoms.

Moderate to Severe Cases

Children with moderate or severe croup, or who aren't quickly responding to home treatments, will often need medical attention, which usually includes administering a steroid to help decrease swelling and inflammation and improve breathing. An injection of dexamethasone has been the standard way of administering this steroid, but new studies have shown that an oral steroid (Prelone, Orapred, etc.) or steroid delivered by a nebulizer (Pulmicort) may also be effective.

For children with severe respiratory distress, treatment in a hospital setting may include a breathing treatment with racemic epinephrine. Because there is a risk of a rebound and worsening breathing, children are usually observed for two to four hours after receiving racemic epinephrine. Children who continue to have difficulty breathing, or who require more than one treatment, are usually hospitalized.

A newer treatment that is being researched is the use of a helium-oxygen mixture (heliox) for children with severe croup, but its efficacy is still unclear.

What to Know About Croup

In addition to the above tips on recognizing and treating croup, other things to know about this infection include:

  • Children who get diagnosed with croup multiple times each year might also need to be evaluated for asthma.
  • If your child is getting croup often, they may have spasmodic croup (acute spasmodic laryngitis), which can be triggered by viruses, allergies, or reflux. Although they may have trouble breathing, children with spasmodic croup often don't have a fever and get better quickly after several hours.
  • The main symptoms of croup typically last only 2 to 5 days, but more rarely, they can last several weeks. Once the barking cough and difficulty breathing improve, your child may continue to have cold symptoms for 7 to 10 days.
  • Unless your child has a secondary bacterial infection, such as an ear infection, antibiotics will not be effective against the viruses that cause croup.
  • Your child can get croup more than once. There are many viruses that can cause croup, including parainfluenza, adenovirus, respiratory syncytial virus (RSV), and influenza (the flu virus), and there are multiple subtypes of each virus. So, while your child may become immune to one of these viruses after having croup, they can contract another one at a later time.

Although there is no vaccine (except for the seasonal flu vaccine) or medication that can prevent your child from getting croup, you might decrease the chance that your child will get croup by limiting their exposure to other people who are sick. Also, encouraging frequent hand-washing and not sharing foods and drinks can help to lessen your child's chances of getting croup or other illnesses.

When to Call the Doctor

In most cases, croup can be treated at home. However, it is a good idea to call your doctor to review their symptoms and to find out if they want your child to come in for evaluation. In moderate to severe cases, medications or other treatments may be needed.

Call 911 right away if your child exhibits any of the following symptoms:

  • Difficulty (or stopping) breathing
  • Difficulty swallowing
  • Drooling excessively
  • Extreme weakness or sluggishness
  • Fingers, nose, or mouth turning blue

A Word From Verywell

While it can be alarming to wake up to your child making a barking cough or struggling for a full breath, trust that croup is a very common and usually mild illness. Consult your doctor with any concerns or if your child's breathing is labored.

Easing your own worry over their symptoms is especially important as you not being stressed will cut back on your child's fears, which in turn, tends to reduce the severity of their cough and difficulty with breathing. Your child (and their caregivers) may have a few sleepless nights ahead, but after that, they will soon feel much better.

5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Family Physicians. Condition: croup.

  2. Zoorob R, Sidani M, Murray J. Croup: An overview. Ameri Fam Phys. 2011;83(9):1067-73.

  3. Bjornson CL, Johnson DW. Croup in childrenCMAJ. 2013;185(15):1317-1323. doi:10.1503/cmaj.121645

  4. Johnson DW. CroupBMJ Clin Evid. 2014;2014:0321. PMID:25263284

  5. Moraa I, Sturman N, McGuire TM, van Driel ML. Heliox for croup in childrenCochrane Database Syst Rev. 2018;10(10):CD006822. doi:10.1002/14651858.CD006822.pub5

Additional Reading

By Vincent Iannelli, MD
Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.