What are the symptoms of croup?

Croup is usually caused by a virus and at first shares some of the symptoms of a cold including:

  • sore throat
  • cough
  • runny nose
  • fever (temperature of 38.5°C or higher). Fever is not always present.
The symptoms characteristic of croup usually develop after 1–2 days. Your child’s windpipe (trachea) may also swell just below the voice box (larynx). The swelling can also cause a hoarse or croaky voice and sometimes difficulty breathing.

Most cases of croup are mild but the infection can become serious and need urgent treatment.

Children with Down syndrome or a condition that normally causes breathing problems are more likely to develop severe croup. This means that your doctor may recommend that your child go to hospital even if their symptoms are mild.

Symptoms of mild croup include:

  • a bark-like cough
  • abnormally noisy high-pitched breathing (stridor) only when your baby is active or upset
  • normal breathing rate.

Symptoms of moderate croup include:

  • a bark-like cough
  • abnormally noisy high-pitched breathing (stridor) even when your baby is resting
  • difficulty breathing
  • rapid heart beat.

Seek emergency medical treatment if your child:

  • has severe difficulty breathing or is exhausted from trying to breathe
  • has a worsening cough or abnormally noisy high-pitched breathing (stridor) even when resting
  • is restless, distressed and agitated
  • has a fever (a temperature of 38.5°C or higher)
  • is pale and sweaty or their skin begins to turn blue around the lips or fingernails
  • is breathing very fast (they may be too breathless to feed or talk)
  • stops breathing for more than 10 seconds at a time
  • is abnormally drowsy or sleepy and can’t be woken up, or does not stay awake after being woken.

These signs may mean that your child is not getting enough oxygen, and needs immediate medical attention.

How long will my child’s symptoms last?

Croup symptoms usually go away on their own within 48 hours, but they can sometimes last for up to a week.

The symptoms are usually worse at night.

Call your doctor or seek emergency medical attention if you notice your child is having difficulty breathing or their symptoms are getting worse.

Find out more about the medicines and treatments for croup and how to manage the symptoms of croup.

  • Respiratory Expert Group. Therapeutic guidelines: Croup. In: eTG complete [online]. Melbourne: Therapeutic Guidelines Limited, 2012 (accessed 12 April 2012).
  • Russell KF, Liang Y, O'Gorman K, et al. Glucocorticoids for croup. Cochrane Database of Systematic Reviews 2011, Issue 1. DOI: 10.1002/14651858.CD001955.pub3.
  • NHS Choices – croup: www.nhs.uk/Conditions/Croup/Pages/Symptoms.aspx (accessed 18 April 2012).