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Children’s Croup and Stridor

Patient information A-Z

Severe croup

  • Severe breathing difficulties
  • The centre of the chest is sucking in with each breath
  • Drooling
  • They’re too breathless to feed or talk
  • You can’t hear sounds of breathing
  • Worsening stridor
  • Distress or agitation
  • Abnormal drowsiness and sleepiness
  • Dark, blue-tinged or pale skin
  • A rapid heartbeat or a falling heart rate
  • 0.25% of children

What should I do?

Croup cough

  • Bark like cough
  • A hoarse or croaky voice.


  • Treat at home with simple treatments
  • Ask pharmacy for advice if needed.
  • Do not give cough syrups as these can make your child drowsy and mask the symptoms of the airway narrowing.

Mild croup

  • Stridor when the child cries or coughs
  • Stridor which is continuous.
  • The child is NOT working harder to breath.


  • Ask for an appointment with your GP or, if it is the middle of the night, the GP out of hours service via 111.

Moderate Croup

  • The stridor is continuous
  • You notice the child is working harder to breath
  • Less than 5% of children


Seek immediate medical attention either with your GP or go the Emergency Department


Who gets croup?

Croup is common between the ages of one and three years of age. As children become older their breathing tubes become bigger and firmer so they are not as easily affected. Croup is uncommon after the age of six.

What are the symptoms of croup?

Symptoms are often fairly mild. Most children will have a sore throat, runny nose and a temperature. They will also have a bark like cough and a hoarse or croaky voice. Sometimes croup may become more severe and children may develop stridor.

What is Stridor?

Stridor is a noise that can occur as a child breathes. It is usually a harsh grating sound. Sometimes it may be a soft sound. The voice box (larynx), and windpipe (trachea), connect the mouth to the top of the lungs. Infections in this area can cause a narrowing of the tubes which creates the breathing noise. Stridor is most noticeable when the child cries, coughs or is distressed. Symptoms tend to be worse at night.

What causes stridor?

The commonest cause is a viral infection causing croup. Other causes are bacterial infections of the voice box or windpipe.

In Hospital

Some children with stridor will be given a medication called dexamethasone which helps reduce the swelling of the windpipe.

Simple treatments

  • Cold drinks in small frequent amounts to keep your child hydrated.
  • Cold air e.g. outside
  • Pain relief
  • Avoid activity as this may make symptoms worse
  • Steaming makes no difference and every year children sustain scalds from steam burns

How to spot if your child is working harder than normal to breathe

  • Sucking motion between the ribs with breathing.
  • Using their tummy to breathe more than usual.
  • Sucking in of the neck with breathing.
  • Centre of the chest sucking in with each breath- this is a sign of severe difficulty.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151