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Health · 20 September 2026

Is my child’s cough serious? Coughs, colds and breathing

Most coughs are a cold, and they last longer than you’d think. The sound of a cough tells you a little. How hard your child is working to breathe, and whether they are still feeding, tells you what matters.

A cough is the body clearing the lungs and airways. In children it is usually caused by a cold or another virus, it needs no treatment, and it gets better without antibiotics. Small children catch a lot of colds, so through the winter it can feel as if the cough never stops. The useful skill is telling the ordinary cough from the few that need a doctor, and that is mostly about breathing, not about coughing.

How long it lasts

A cold usually improves in 1 to 2 weeks, and it can take longer in young children. The cough outlasts it: a cough usually clears up on its own within 3 to 4 weeks, and a dry cough commonly hangs on for several weeks after the cold has gone. A child who is well in every other way and still coughing in week three is following the normal course.

See a doctor about a cough that has lasted more than 3 weeks, a cold that is no better after 10 days, or a high temperature that has lasted more than 3 days.

Four coughs worth telling apart

A cold

A runny or blocked nose, sneezing, a cough, sometimes a temperature. Any age. Look after them at home.

Bronchiolitis

Babies and children under 2, most often in the first year. It starts as a cold, then the cough worsens, breathing gets faster and noisier (wheezing or crackling), and feeding gets harder. It is usually worst between days 3 and 5. Usually mild and managed at home, but watch the breathing and the feeding closely.

Croup

Mostly 6 months to 6 years. A barking cough like a seal, a hoarse voice, and a high-pitched rasping sound when breathing in. It often comes on at night. Get medical advice the same day, because a doctor may give medicine that shortens it.

Whooping cough

A cold for about a week, then coughing bouts that last minutes and are worse at night, sometimes with a “whoop” as they gasp for breath. Babies under 3 months may not whoop. See a doctor, and urgently if your baby is under 6 months.

Bronchiolitis is usually caused by a virus called RSV, which almost every child catches before they are two. It is not usually serious.

Watch the breathing

These are the signs that a child is working hard to breathe. Any of them means get help, and the list further down says how fast.

UK guidance for young children with a fever gives numbers for “faster than expected”, counted while the child is resting rather than crying:

AgeBreaths in a minute
Under 6 monthsMore than 60
6 to 12 monthsMore than 50
Over 12 monthsMore than 40

From NICE’s guideline on fever in under-fives. Its bronchiolitis guideline treats more than 70 breaths a minute as severe.

Then watch the feeding and the nappies. A baby who is short of breath struggles to feed. Taking less than half their usual amount, or no wet nappy for 12 hours, is a reason to be seen the same day.

Looking after them at home

  1. Fluids and rest. For a baby, offer smaller feeds more often. A blocked nose makes feeding hard work, so saline nose drops or spray before a feed can help.
  2. Upright when awake. It makes breathing easier. With croup, sit them upright and keep them calm, because crying makes it worse.
  3. Honey, but only over 12 months. One to two teaspoons before bed may ease a night-time cough. Never give honey to a baby under 1: it carries a rare but serious risk of botulism. Don’t give hot drinks to small children.
  4. No smoke. Smoking or vaping around a child makes a cough worse and bronchiolitis more severe.
  5. Check on them, including overnight. Croup can worsen quickly and is often worst at night.
  6. Steam depends on what it is. For a blocked nose from a cold, the NHS suggests sitting in the bathroom with a hot shower running, and never a bowl of hot water, because of scalds. For croup its advice is the opposite: don’t use steam.

Medicines

Never give aspirin to anyone under 16. Check the label of anything you did not buy specifically for children.

Red flags: get help now

Call your emergency number or go straight to an emergency department if your child:

Get medical advice the same day (in the UK, your GP or NHS 111) if:

Be quicker to ask for a baby under 6 months, a child who was born prematurely, or one with a heart or lung condition or a weakened immune system. Bronchiolitis is more likely to be serious for them.

Nursery, school and spreading it

A cold is infectious until the symptoms have gone, usually 1 to 2 weeks. Keep a child home while they have a fever or are too unwell for a normal day. There is no need to keep them home for the cough that lingers afterwards, which can go on for weeks.

Whooping cough is different: stay off until 48 hours after starting antibiotics, or 3 weeks after the cough started without them. It is also what the routine childhood vaccines protect against, and a vaccine in pregnancy protects a newborn in the first weeks. A vaccine against RSV is offered in pregnancy in the UK too.

Common questions

How long does a child’s cough last?

Longer than most parents expect. A cold usually improves in 1 to 2 weeks, but the cough that comes with it can take 3 to 4 weeks to clear, and a dry cough often lingers for several weeks after the cold has gone. See a doctor about a cough that has lasted more than 3 weeks, or sooner if it is getting worse rather than better.

Can I give my child cough medicine?

Not under 6. The UK medicines regulator says over-the-counter cough and cold medicines should not be used in children under 6, and for ages 6 to 12 only with a pharmacist’s advice. The American Academy of Pediatrics says not under 4, and from 4 to 6 only if a doctor recommends it. There is little evidence they help at any age. Paracetamol or ibuprofen ease discomfort and fever but do not treat a cough.

Can I give honey for a cough?

Only to a child over 12 months. Honey can carry a rare but serious risk of botulism for babies under 1. For older children, one to two teaspoons before bed may ease a cough at night. Don’t give hot drinks to small children.

How fast is too fast for a child’s breathing?

UK guidance for young children with a fever treats these as faster than expected, counted while the child is resting: more than 60 breaths a minute under 6 months, more than 50 from 6 to 12 months, and more than 40 over 12 months. Fast breathing at rest is a reason to get medical advice the same day. Breathing that is hard work, with grunting or the skin sucking in under the ribs, is an emergency.

Doodlebug keeps the timeline

Log the cough as a symptom, each feed, each wet nappy and each temperature in two taps. When you ring for advice and they ask how much your baby has fed since yesterday, or when the last wet nappy was, the answer is on one timeline instead of in your head. It’s free on the App Store.

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Sources

Doodlebug is a tracking app, not a medical service. This page is general information drawn from published guidance and is not advice about your child. Doses, age limits and the name of your emergency number vary by country: follow the pack and your own doctor. If you are worried about your child, get medical help.