It’s the middle of the night and your baby suddenly has a cough that sounds like a seal barking. If that’s where you are right now, take a breath. This guide to croup in babies explains what that bark usually means, what you can do at home tonight, and the exact signs that mean it’s time to call your pediatrician or 911. Most cases of croup can be cared for at home with your doctor’s guidance, according to MedlinePlus.
Quick answer: croup in babies
- Croup is swelling of the voice box and windpipe, usually caused by a virus. It causes a barking, seal-like cough, a hoarse voice, and sometimes a high-pitched sound when breathing in (called stridor).
- It mostly affects children from about 3 months to 5 years old, and it’s most common from October through April.
- Symptoms are usually worse at night. Croup often lasts up to 3 nights, sometimes up to 7, and the first one or two nights are usually the hardest.
- Tonight: keep your baby calm, hold them upright while they’re awake, offer feeds, and treat fever as your pediatrician advises. Cough medicines and antibiotics don’t help croup.
- Call your pediatrician if you think your baby has croup. Call right away if your baby is under 3 months old.
- Call 911 if your baby is struggling to breathe, has noisy breathing even while calm and resting, has skin pulling in between the ribs, has blue or gray lips or skin, is drooling or can’t swallow, or is very sleepy and hard to wake.
What croup sounds like
Croup often starts like a regular cold: a runny nose, a mild fever and a cough. After a day or two, the cough changes. The NHS describes it as a barking cough that can sound like a seal. Other common signs are:
- a hoarse voice or hoarse cry;
- a high-pitched, rasping sound when your baby breathes in (stridor);
- symptoms that get worse at night.
Some children get a type called spasmodic croup, which can start suddenly without a fever, according to MedlinePlus. Crying and being upset can make the cough and the noisy breathing worse, the American Academy of Pediatrics (AAP) explains. That’s why one detail matters most: noisy breathing that happens even when your baby is calm and resting is a reason to get emergency help.
What to do tonight: a calm step-by-step plan
- Stay close and keep your baby calm. Hold them, rock them and talk softly. The AAP notes that crying can worsen the cough and the work of breathing.
- Hold your baby upright while they’re awake. The NHS advises keeping a child with croup upright. When your baby falls asleep, place them on their back in their own crib or bassinet as usual. The AAP advises against inclined sleep surfaces and against sleep in car seats, swings or products not made for infant sleep, so don’t prop your baby up on pillows.
- Offer feeds often. Breast milk or formula keeps your baby’s fluids up. Both the NHS and the AAP mention making sure your child drinks enough.
- Treat fever carefully. A fever is a temperature of 100.4°F (38°C) or higher. If your baby is under 3 months old and has a fever, call your pediatrician right away. Ibuprofen is only for babies older than 6 months. For children under 2, the AAP advises asking your pediatrician or pharmacist for the right dose.
- Skip cough syrups and don’t ask for antibiotics. The AAP says cough syrups are not useful for croup and may cause harm, and antibiotics don’t help because croup is almost always caused by a virus.
- Check on your baby through the night. The NHS advises checking regularly, including overnight. Keep the warning signs below somewhere you can see them.
Steam, cold night air and humidifiers: what the evidence says
You may have heard that a steamy bathroom or a walk in cold air helps croup. Here’s what official sources actually say:
- Steam: the AAP calls the steamy bathroom an older recommendation and says no studies show it works. The NHS goes further and advises not to put your child in a steamy room or have them breathe in steam.
- Cool night air: MedlinePlus says moist or cool air may make a child more comfortable, but studies have not shown that it reduces symptoms.
- Humidifiers: if you use one for comfort, MedlinePlus advises a cool-mist humidifier for children (warm-mist units can cause burns), placed several feet from the crib and drained and cleaned every day.
What the sources agree on is simpler: keep your baby calm, offer fluids, and know the warning signs.
How long does croup last in babies?
MedlinePlus says croup usually lasts up to 3 nights and occasionally up to 7, with the first one or two nights usually being the worst. The NHS says croup usually gets better on its own within 48 hours. Rarely, it can last longer. Talk to your pediatrician if croup lasts longer than a week or keeps coming back.
Home, call, or 911: a quick check
| What you notice | What to do |
|---|---|
| Barking cough and hoarse voice, noisy breathing only when upset, baby calms with comfort and is feeding | Comfort care at home and call your pediatrician for advice |
| Baby is under 3 months old with croup symptoms, or has a fever of 100.4°F (38°C) or higher | Call your pediatrician right away |
| Not improving, getting worse, more irritable, lasting longer than a week, or coming back often | Call your pediatrician |
| Struggling to breathe, noisy breathing at rest, skin pulling in, blue or gray lips or skin, drooling or trouble swallowing, very sleepy or can’t be calmed | Call 911 |
Related: humidifier for a baby room: is it safe, and which type to use.
When to talk to your doctor
Call your pediatrician if you think your baby has croup. A doctor can check your baby’s breathing and may prescribe medicine. Call sooner, or get help right away, if:
- your baby is younger than 3 months;
- your baby under 3 months has a temperature of 100.4°F (38°C) or higher;
- symptoms aren’t improving or are getting worse;
- croup lasts longer than a week or keeps coming back.
Call 911 if your baby:
- is struggling to breathe or the breathing sound gets louder with each breath;
- has stridor (a harsh, high-pitched sound) while calm and resting;
- has skin pulling in between the ribs or at the neck with each breath;
- has bluish or gray lips, skin or fingernails;
- is drooling or has trouble swallowing;
- is very sleepy, hard to wake, limp, or very distressed and can’t be calmed.
For more on other warning signs, see when to call the pediatrician and our health and safety guides.
Frequently asked questions
Is croup contagious?
Croup is usually caused by common viruses, such as parainfluenza, flu and RSV, according to MedlinePlus. These viruses spread from person to person like a cold, so handwashing and keeping a sick baby home from daycare can help limit the spread.
Can a baby under 3 months get croup?
It’s less common, since croup mainly affects children from about 3 months to 5 years. The NHS notes that children under 3 months may be referred to the hospital. If your young baby has a barking cough or noisy breathing, call your pediatrician right away.
Can my baby get croup more than once?
Yes. The UK Health Security Agency notes that a child can get croup more than once, and that it’s most common in late fall and early winter.
Should I give my baby cough medicine for croup?
No. The AAP says cough syrups are not useful for croup and may cause harm. Ask your pediatrician before giving any medicine to a baby.
What will the doctor do?
The doctor will listen to your baby’s breathing. The AAP explains that a doctor or emergency department may give steroid medicine or breathing treatments, and that a child is usually watched for a few hours after a breathing treatment.
Is croup the same as RSV or bronchiolitis?
Not quite. RSV is one of the viruses that can cause croup, according to MedlinePlus, but RSV can also cause other illnesses. Croup affects the voice box and windpipe. Read our guides to RSV in babies and bronchiolitis in babies for the differences, and how to care for a sick baby at night. For fever, see baby fever: when to worry.
Free printables: get our Safe Sleep Checklist, Feeding & Diaper Log and Hospital Bag Checklist, plus one short tip email a week. Join Babypino Weekly.
Sources
- MedlinePlus (NIH): Croup
- HealthyChildren.org (AAP): Croup in Young Children
- HealthyChildren.org (AAP): Fever Without Fear
- HealthyChildren.org (AAP): How to Keep Your Sleeping Baby Safe
- MedlinePlus (NIH): Humidifiers and health
- NHS: Croup
- UKHSA: A parent’s guide to croup
This article is for general information only and is not a substitute for medical advice. If you’re worried about your baby’s breathing, call your pediatrician, or call 911 in an emergency.