Croup

A cough that sounds like a seal, a hoarse voice and noisy breathing in, often in the middle of the night. Croup sounds terrifying, but most cases are mild and settle within a few days. Calm is the first treatment.

What it is: swelling of the voice box and windpipe from a virus, most often parainfluenza. Other viruses, including flu, RSV and COVID-19, can cause it too. It usually starts like a cold, then the barking cough arrives, often worse at night.

Who gets it: mainly children aged about 6 months to 5 or 6 years. It’s uncommon under 6 months, so younger babies need a doctor to check it really is croup.

How long it lasts: usually 2 to 5 days, worst on the second or third night. Mild croup often settles within 48 hours. A cough can hang around for a few weeks afterwards.

Stridor: the high-pitched, rasping sound when breathing in. Doctors care more about how hard your child is working to breathe and how they look than how loud it is. Quiet breathing in a child who is getting worse can be a bad sign.

The croup ladder

Most croup is mild and managed at home. One dose of steroid medicine works well for anything more than a bark. Hospital is for children who are struggling to breathe.

1. Step 1 · Self-careCalm, upright and fluidsComfort your child and keep them calm, because crying can make breathing harder. Sit them upright on your lap, offer drinks and check on them often, including overnight. Paracetamol or ibuprofen can help with fever or a sore throat.

   Works

   Doesn’t shorten croup, but a calm child breathes more easily. Mild croup often settles on its own within 48 hours

   Cost

   Free, plus a few dollars for pain relief

   How long

   2 to 5 days

   Watch for

   Noisy breathing at rest, the skin between the ribs sucking in, or a child who is getting worse.

   Your calm is contagious. So is panic.

2. Step 2 · GPOne dose of steroid medicineIf there is noisy breathing (stridor), or your child is at higher risk, a doctor usually gives a single dose of an oral steroid: dexamethasone or prednisolone. A barking cough on its own doesn’t need it.

   Works

   Works well. In a Cochrane review of 45 trials, steroids eased croup within 2 hours and meant fewer return visits and shorter hospital stays. A low dose seems to work about as well as a high dose

   Cost

   Low; usually given at the clinic or emergency department

   How long

   Starts working within hours; one dose is usually enough

   Watch for

   Get checked again if noisy breathing at rest comes back after the steroid.

   One small dose, one big exhale for the whole family.

3. Step 3 · HospitalAdrenaline nebuliser and observationFor moderate to severe croup, hospital staff give adrenaline through a nebuliser mask, alongside a steroid, then watch your child for several hours. A few children need extra breathing support.

   Works

   Opens the airway quickly while the steroid kicks in. Children are usually watched for at least 3 to 4 hours after a dose

   Cost

   Free in Australian public hospitals

   How long

   Hours

   Watch for

   Its effect wears off, which is why children are observed before going home.

   The emergency department has seen a lot of seals. They know the drill.

Costs are rough Australian prices in November 2026 and vary by pharmacy and provider. PBS co-payment: $25, or $7.70 with a concession card. Results are typical figures from trials, not promises.

Save your money

Popular, heavily marketed or often asked about, but the evidence is weak or says no.

• Steam, hot showers or humidifiersNot shown to change how bad croup is, and steam can cause serious burns.
• AntibioticsCroup is caused by a virus, so antibiotics don’t help.
• Cough medicines, including codeineNo proven benefit in croup, and they can cause drowsiness and slow breathing.
• X-rays, swabs and blood testsNot needed for typical croup. Doctors diagnose it by listening and looking.

What you can do

• Stay calm and hold your child upright. A story, a cuddle or a favourite show can help.
• Offer drinks often, in small amounts.
• Check on your child during the night, as croup is often worse after dark.
• Give paracetamol or ibuprofen if they are uncomfortable or feverish.
• Know the signs that need urgent help (below) before bedtime.
• If a cough lingers or keeps coming back, see our cough fact sheet.

See your GP if

• You think your child has croup and they have noisy breathing
• Your baby is under 6 months with croup-like symptoms
• Mild croup has lasted more than 4 days
• Noisy breathing comes back after they’ve recovered
• Your child has had severe croup before, or has a condition affecting their airway

See a doctor urgently if

• Noisy breathing (stridor) while resting, not just when upset
• The skin between or under the ribs sucks in with each breath
• They are getting more distressed or can’t be settled
• Croup symptoms are getting worse, not better, after a steroid dose

Call 000 (Australia) or your local emergency number if your child is struggling to breathe, has pale or blue lips or skin, is drooling or can’t swallow, is floppy, unusually drowsy or hard to wake, or prefers to sit forward rather than lie down. Don’t drive yourself if your child is very unwell.

Helpful resources

• healthdirect: CroupSymptoms, treatment and when to call an ambulance. Free, Australia.
• NHS: CroupHome care and urgent warning signs. Free, UK.
• Cough fact sheetWhen a cough lingers. Free, from us.

Evidence and more information

• Royal Children’s Hospital Melbourne: Croup clinical practice guideline
• healthdirect: Croup
• NHS: Croup
• Cochrane 2023: Glucocorticoids for croup in children

Reviewed 4 November 2026. General education, not personal medical advice. Treatment depends on your situation, so talk to your GP, physio or pharmacist.

maladywise.com/croup/