Croup in Children: That Barking Cough at Night
It is 2 AM and your toddler wakes up with a cough that sounds like a barking seal. That frightening sound is almost certainly croup — one of the most common reasons parents rush to the ER at night, and one of the most manageable once you know what it is.
Key takeaways
- Croup is swelling around the voice box caused by a virus — it makes a distinctive barking cough and sometimes noisy breathing (stridor).
- It is worst at night, peaks around night 2–3, and most cases are mild and managed at home.
- Keep your child calm — crying makes the noisy breathing worse. Cool air and comfort are your best home tools.
- Go to the ER for stridor at rest, trouble breathing, drooling, or a bluish color around the lips.
What is croup?
Croup is swelling of the voice box (larynx) and windpipe (trachea), usually caused by a common cold virus (most often parainfluenza). It mostly affects children between 6 months and 3 years old, because their airways are small — even a little swelling makes a big noise.
The hallmark signs:
- A barking cough — harsh and seal-like, unlike any regular cough
- Stridor — a high-pitched whistling sound when breathing in
- Hoarse voice
- Low-grade fever and cold symptoms before the cough starts
Croup often starts like a regular cold for a day or two, then the barking cough appears — usually at night.
Why is croup worse at night?
This is the question I hear most in the ER. Croup classically worsens after midnight for a few reasons: lying flat lets mucus pool around the already-swollen airway, and the body's natural cortisol (which fights inflammation) dips at night. Many children seem almost fine during the day and then bark like a seal at 2 AM. It is alarming, but it is the typical pattern — not a sign things are spiraling.
Home care for croup: what actually helps
- Keep them calm. This is the single most important thing. Crying and agitation tighten the airway and make stridor worse. Hold them upright, speak softly, comfort them.
- Cool night air. The old advice — bundle up and step outside for a few minutes — is safe to try and helps some children. Do not overdo it in extreme cold.
- A steamy bathroom is another traditional remedy. Sit with your child in a bathroom with the hot shower running for 10–15 minutes. Evidence is mixed, but it is harmless and the calm togetherness helps.
- Offer fluids. Keep them hydrated; it keeps airway secretions thinner.
- Fever reducers if needed. Acetaminophen (Tylenol) or ibuprofen (Motrin/Advil, only if over 6 months) for comfort — see our medication dosing guide for weight-based dosing.
- Honey for cough (only if over 12 months old) can soothe the throat — a half teaspoon as needed.
Avoid these
- Over-the-counter cough and cold medicines — not recommended for young children and do not help croup.
- Vicks or menthol rubs near the nose — can irritate small airways.
- Forcing them to lie flat — sitting upright is easier for breathing.
Croup vs. bronchiolitis: how to tell them apart
Parents often confuse these two. Croup affects the upper airway — barking cough, stridor when breathing in, hoarse voice, worst at night. Bronchiolitis affects the lower airways (smallest air tubes in the lungs) — wheezing when breathing out, fast or labored breathing, mostly in babies under 2. See our full comparison: Croup vs. Bronchiolitis: How to Tell Them Apart.
How long does croup last?
The barking cough usually peaks on night 2 or 3 and then steadily improves over 3–5 days. A mild lingering cough can hang on for up to two weeks. Croup can recur — some toddlers get it several times, because small airways swell easily. The good news: children outgrow it as their airways get bigger, usually by age 5 or 6.
When should I call the pediatrician about croup?
- Stridor (noisy breathing in) that persists during the day, not just at night
- The barking cough lasts more than 5 days without improving
- Your child is not drinking well or seems unusually tired
- You are simply worried — parental instinct counts
When should I take my child to the ER for croup?
- Stridor at rest — noisy breathing even when calm and quiet, not just when crying
- Trouble breathing: ribs pulling in with each breath (retractions), belly breathing, or fast breathing that does not settle
- Drooling or trouble swallowing — this can signal something more serious than croup (like epiglottitis); do not try to look in the throat, go to the ER
- Bluish or gray color around the lips or face
- Your child is unusually sleepy, limp, or hard to wake
In the ER, the standard treatment for moderate-to-severe croup is a single dose of oral dexamethasone (a steroid that reduces airway swelling) — it works within hours and often prevents an overnight stay. Severe cases may also get nebulized epinephrine. Both are quick, safe, and very effective.
Related reading: croup vs. bronchiolitis, breathing problems in children, and fever in children.
Sources
This guide was reviewed against guidance from:
Frequently asked questions
What does croup sound like?
Croup causes a harsh, barking cough that sounds like a seal. Children may also make a high-pitched whistling sound when breathing in, called stridor, and have a hoarse voice.
Why is croup worse at night?
Croup symptoms typically worsen at night because lying flat and cooler nighttime air can increase airway swelling. Many children are fine during the day and then develop the barking cough after midnight.
Does cold air help croup?
Cool night air may temporarily ease croup symptoms for some children, which is why the old advice was to bundle up and step outside. It is safe to try, but it is not a treatment — call your pediatrician if symptoms persist.
How long does croup last?
The barking cough of croup usually peaks around night 2 or 3 and then improves over 3 to 5 days. A mild lingering cough can last up to two weeks.
Can croup come back?
Yes. Some children, especially ages 1 to 3, get croup several times because their airways are small and swell easily. Recurrent croup usually becomes less severe as the child grows.
Reviewed by Ali Ozcan, MD, MBA
Board-certified pediatric emergency medicine physician and creator of ER4Kids. This guide reflects the same trusted, evidence-based guidance Dr. Ozcan provides to families in the emergency department.
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