Overview
Croup is a common illness that affects babies and young children. Swelling around the voice box and windpipe causes a barking cough, a hoarse voice, and sometimes a harsh sound when breathing in called stridor. Most cases are mild, but some children need urgent treatment.
How common is it?
Croup is common in young children, especially between about 6 months and 3 years of age, though older children can get it too.
Causes and risk factors
Croup is usually caused by a viral infection. The infection makes the airway below the vocal cords swell, which is why breathing can sound noisy and the cough can sound barky.
Common risk factors
- Age between about 6 months and 3 years
- Recent cold-like illness
- Autumn and winter viral season
- Previous croup episodes
Symptoms
- A barking cough
- A hoarse voice
- A high-pitched noise when breathing in
- Cold symptoms such as a runny nose or fever at the start
- Symptoms that are often worse at night
- Breathing that becomes noisy or more difficult when upset
When to see a doctor
Call NHS 111, a GP, or your local clinician if you think your child has croup, especially if symptoms are getting worse or not improving. Get emergency help if your child has stridor while resting, is struggling to breathe, is drooling or finding it hard to swallow, looks blue, grey, or very pale, or is unusually sleepy, floppy, or hard to wake.
Diagnosis
Croup is usually diagnosed from the symptoms and the way the child is breathing. Tests are not usually needed unless a clinician is worried about another cause of airway problems.
Treatments
Keep the child calm and comfortable
Keeping a child calm can make breathing easier because crying often worsens symptoms. Offer fluids and keep checking them, including overnight if symptoms are active.
Medicines for fever or discomfort
Paracetamol or ibuprofen may help if they are suitable for the child's age and situation. A clinician may give steroid medicine such as dexamethasone to reduce swelling.
Hospital treatment for severe croup
Children with more serious croup may need hospital care, breathing treatment with adrenaline, and observation while the swelling settles.
Self-care and lifestyle
- Sit your child upright if that helps them breathe more comfortably
- Do not use steam or hot vapour treatments
- Do not give cough syrups unless a clinician advises it
- Check your child regularly at night while symptoms are active
Prevention
Handwashing, avoiding close contact with people who are ill, and keeping up with routine vaccinations can reduce some infections that can lead to croup or other serious airway illness.
Sources and review
Last reviewed: 28 July 2026 by Living Diabetes Editorial Team. This guide was checked against current patient and professional guidance. It is educational and does not replace care from your own healthcare team.