Breathing Problems in Children: Croup, Bronchiolitis, and Red Flags
Few sounds frighten a parent like a child struggling to breathe — the barking cough of croup at midnight, the wheeze of bronchiolitis, the ribs pulling in with every breath. This guide will help you recognize what you are seeing and, most importantly, know when it is an emergency.
How can I tell if my child is having trouble breathing?
Normal breathing is quiet and easy. Signs of respiratory distress include:
- Retractions — the skin pulling in between the ribs, under the ribs, or at the neck with each breath
- Nasal flaring — nostrils widening with each breath
- Grunting — a short grunt with each exhale
- Breathing much faster than usual for their age
- Stridor — a harsh, high-pitched sound when breathing in
- Wheezing — a whistling sound when breathing out
- Trouble speaking in full sentences, or pausing to breathe while drinking (babies)
Call 911 or go to the ER immediately if:
- Lips, tongue, or face turning blue or gray
- Severe retractions, grunting, or your child cannot catch their breath
- Stridor at rest (not just when crying or coughing)
- Your child is limp, unresponsive, or struggling to stay awake
- Pauses in breathing
- Drooling and cannot swallow, with trouble breathing (possible epiglottitis — keep them calm and upright, do not try to look in the throat)
What is croup?
Croup is swelling of the voice box and windpipe, usually from a virus. Its trademark is a barky, seal-like cough, a hoarse voice, and stridor — often arriving suddenly in the middle of the night in children 6 months to 3 years old.
What helps at home for mild croup: keep your child calm (crying worsens stridor), try cool night air or a steamy bathroom, offer fluids, and use fever reducers if needed. Many parents find a few minutes in the cool outdoor air helps. Seek care promptly if there is stridor at rest, retractions, or your child seems to be working hard to breathe — the ER can give a steroid and nebulized epinephrine that work quickly.
What is bronchiolitis?
Bronchiolitis is inflammation of the small airways, most often caused by RSV, and it mainly affects babies under 2. It starts like a cold, then develops into wheezing, fast breathing, and poor feeding over a few days. There is no antibiotic for it — care is supportive: suction the nose with saline before feeds, offer small frequent feeds, and watch breathing closely.
Babies with bronchiolitis need medical evaluation if they are breathing fast or with retractions, feeding poorly, or are under 3 months old. Prevention matters: handwashing and keeping sick contacts away from young infants reduce RSV spread.
What about asthma flare-ups?
If your child has asthma, follow their asthma action plan and use their rescue inhaler as prescribed. Seek emergency care if the rescue medicine is not working, breathing is getting worse, or they cannot speak or play normally. If your child has never been diagnosed with asthma but has recurrent wheezing episodes, mention it to your pediatrician.
Related reading: croup vs. bronchiolitis (blog), fever in children.
Sources
This guide was reviewed against guidance from:
Frequently asked questions
What does croup sound like?
Croup's signature is a harsh, barking cough that sounds like a seal, often with a hoarse voice and a high-pitched squeak (stridor) when breathing in. It typically strikes suddenly at night.
Does cold air really help croup?
Many parents find a few minutes of cool night air eases croupy breathing. Keep your child calm and bundled, and seek care if there is stridor at rest or labored breathing.
What is the difference between stridor and wheezing?
Stridor is a harsh sound when breathing IN, from the upper airway (classic in croup). Wheezing is a whistly sound when breathing OUT, from the lower airways (classic in bronchiolitis and asthma).
When should I take my wheezing baby to the doctor?
Any wheezing in a baby deserves a call to the pediatrician, and prompt evaluation if there are retractions, fast breathing, poor feeding, or your baby is under 3 months old.
My child is breathing fast but seems okay. Is that an emergency?
Fever and crying both speed up breathing. But persistent fast breathing with retractions, nasal flaring, grunting, or difficulty feeding/talking needs urgent evaluation — when in doubt, get checked.
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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