By Dr. Corey A. Fish (He/Him)
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How severe is Croup?

The severity of Croup is variable. Many cases of Croup resolve on their own, but fairly often, Croup is severe enough to warrant a visit to urgent care. In a few cases, serious breathing problems can occur and emergency room care is needed.

What causes Croup?

Croup is caused by a viral infection, usually a parainfluenza virus. The virus infects the upper airway and causes the area around the vocal cords, windpipe, and bronchial tubes to swell. When your kiddo coughs, it forces air through the swollen vocal cords, creating Croup’s distinctive “barking” cough.

Who gets Croup?

Most kids who get Croup are between 6 months to 3 years old. They have tiny airways, so Croup’s distinctive swelling affects them more than in older kids and adults.

Is Croup contagious?

Very contagious
Spreads by exposure

The viruses that cause Croup are contagious and can spread easily through coughing or sneezing, or boogers. In adults, the viruses usually cause cold-like symptoms. Young kiddos in your household can be at risk of Croup. Kiddos are contagious for three days after symptoms begin or until the fever is gone.

How do you know if your child has Croup?

Common and most noticeable symptoms

Croup usually starts as a cold. If there is enough inflammation, kids develop Croup. Croup symptoms usually get worse at night and tend to last for 3-5 days.

Loud “barking” cough. It sounds a bit like a seal’s bark.


Hoarse or raspy voice

Noisy breathing

When it's time to take your kiddo to their primary care provider or an urgent care clinic

Croup symptoms affect kiddos' breathing, so it’s important to keep an eye on them to see if things are getting worse. Seek medical care if you notice any of these symptoms.

Noisy, or squeaky sounds when inhaling or exhaling

Drooling, or having trouble swallowing

Agitated and whiny, or tired and listless

Breathing at a faster rate than usual, which may seem like panting

When it’s time to go to the ER

Struggling to breathe

Blue or grayish skin around the nose, mouth, or fingernails

How to protect your child from Croup

Since Croup is caused by viral infections, use the same methods that you use to protect from cold and flu; wash hands, stay away from sick people, and teach your kiddo to sneeze into their elbow—we like to tell them it’s a “sneeze pocket.”

What to do if your child has Croup


  • The most important thing you can do for your kiddo if they have Croup is to stay calm and help them feel calm too. Crying and agitation can make Croup worse, so think about what your kiddo loves. Snuggles? Nursing? Lullabies? A favorite stuffie? A new movie? Keeping things calm can keep Croup from getting worse.
  • Humid air can also soothe coughs, so sit with your kiddo in the bathroom with a steamy shower going, or run a cool-mist humidifier.
  • Keep kiddos hydrated. For babies, offer breastmilk or formula often. For older kiddos, soup or a popsicle can be more enticing than water.
  • Breathing cool night air can also help symptoms. Take your child outside (fully clothed of course) and let them breathe in the cool air. Standing in front of an open freezer door and letting them breathe there can also mimic this if you live in a place where nights are warm.

When to seek medical care

Most younger children will need to go to the doctor with Croup, so it’s a good idea to check in with your primary care provider if you suspect Croup so that they can help you monitor your kiddo’s symptoms.


Usually Croup lasts 3-5 days. If it’s lasting longer, it’s important to see a healthcare provider.

DisclaimerThis illness guide is not a substitute for professional medical advice, diagnosis or treatment.
911If you think your child may have a life threatening emergency, immediately call your doctor or dial 911.
Headshot of Dr. Corey A. Fish, MD, Founder and Chief Medical Officer, He/Him
Dr. Corey A. Fish (He/Him)

Dr. Corey Fish attended the University of Washington School of Medicine before traveling to Austin, Texas for his pediatric residency at Dell Children’s Medical Center of Central Texas. Now a practicing pediatrician with over 10 years of experience Dr. Fish is passionate about delivering high-quality urgent and after-hours care for children. When he’s not working, you’ll find him cycling with his wife, backcountry skiing, and playing guitar.

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