Croup in babies: what the barking cough means and when to call 111

5 min read

Quick answer: A barking cough that sounds like a seal, with a hoarse voice and a rasping sound when breathing in, usually means croup. If you think your baby has it, call 111 or ask for an urgent GP appointment because they may need medicine. Call 999 if they're struggling to breathe or look blue or grey.

What parents need to know

Croup usually starts like an ordinary cold. After a few days of a temperature, runny nose and cough, the barking cough begins, and the NHS says it's often worse at night. The Red Cross says croup mostly affects children aged 6 months to 3 years. Most cases are in one-year-olds, but babies as young as 3 months can get it.

The cough comes from swelling in the voice box and airway. Crying can make the noise and the breathing worse, so keeping your baby calm helps. Most croup is mild, and the NHS says it usually gets better on its own within 48 hours.

How croup usually starts

The typical pattern

Cold symptoms come first. After a few days your baby may develop a barking cough, a hoarse voice and a high-pitched, rasping sound when they breathe in. Some babies also have difficulty breathing. The NHS notes that the symptoms are often worse at night, so many parents first hear the cough after bedtime.

St John Ambulance describes the voice as croaky. The Red Cross says the cough can also sound like crowing or whistling.

Is it croup or something else?

Other illnesses can cause similar symptoms. The NHS uses these differences to tell them apart.

Symptoms	Possible cause
Barking cough, hoarse voice, rasping sound when breathing in	Croup
Runny nose, sneezing, cough, temperature	Cold
Cold-like symptoms with wheezing, fast breathing, not feeding	Bronchiolitis
Bouts of coughing with a "whoop" when breathing in	Whooping cough

Call 111 or your GP if you think it's croup

The NHS advises calling 111 or asking for an urgent GP appointment if you think your child has croup, even when it seems mild. A doctor may give your child medicine to shorten the illness.

If your child is under 5, phone 111 instead of using 111 online, which is for people aged 5 and over. Call again or go back to your GP if your child gets worse, or doesn't get better after being seen. Babies under 3 months, and children who are more seriously ill, are sometimes referred to hospital.

Looking after mild croup at home

Once 111 or a doctor has confirmed it's mild croup, the NHS suggests these steps to help your child feel better.

Keep them upright. Sit your child up and try not to let them lie down. St John Ambulance suggests sitting them on your knee with their back supported
Keep them calm. Comfort them if they're upset. Crying can make croup symptoms worse
Give them plenty of fluids
Check on them regularly, including during the night
Give paracetamol or ibuprofen for a high temperature or discomfort, using the dose on the packet for their age
Skip the steam. Don't put your child in a steamy room or get them to breathe in steam. The NHS advises against it

When to call 999 or go to A&E

The NHS says to call 999 or go to A&E if your child:

is struggling to breathe. You may hear grunting, see their tummy sucking in under the ribcage, or notice that their breathing sounds different
has blue, grey, pale or blotchy skin, lips or tongue. On brown or black skin this may be easier to see on the palms or the soles of the feet
is sleepier than normal, hard to wake, or unusually quiet and still
is limp or floppy, or isn't responding like they usually do
is very upset or restless, is having difficulty breathing and can't be calmed down
is drooling more than usual, finds it hard to swallow, or wants to sit up rather than lie down

Getting there safely

Don't drive to A&E yourself. Ask someone else to drive, or call 999 and ask for an ambulance. St John Ambulance advises watching your child's breathing and how they respond until help arrives.

If your child is unwell and you think something is seriously wrong, the NHS says to get help straight away. If you're worried but unsure, call 111.

Practical checklist

Call 111 or ask for an urgent GP appointment if you suspect croup
Phone 111 rather than using 111 online for a child under 5
Keep your child sitting upright and as calm as you can
Offer plenty of fluids and check on them through the night
Avoid steam treatments
Call 999 if they're struggling to breathe, look blue or grey, or are floppy or hard to wake

Frequently asked questions

How long does croup last?

The NHS says croup usually gets better on its own within 48 hours. The Red Cross notes that a single episode can last hours or days.

Can croup come back?

Yes. According to the Red Cross, croup can flare up now and again after a child has had it, and it stops completely as they get older.

Sources & further reading

nhs.uk: Croup
Source checked 2026-10-04
nhs.uk: When to get urgent medical help for babies and children under 5
Source checked 2026-10-04
nhs.uk: When to use NHS 111 online or call 111
Source checked 2026-10-04
redcross.org.uk: Learn first aid for a baby or child with croup
Source checked 2026-10-04
sja.org.uk: Croup
Source checked 2026-10-04

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.