Signs of serious illness in children

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

You know your child best. You can recognise changes in mood, behaviour, activity and appetite that indicate your child may be developing an illness. If there are signs that your child is slightly unwell and you're not sure what you do, call HealthDirect.

If your child's health is getting worse, contact your family doctor. 

When should I be concerned?

There are general features of a more serious illness which should prompt you to see a doctor more urgently. These include:

  • decreased alertness and irritability
  • breathing difficulties 
  • changes in skin colour and appearance
  • drinking less than usual or not passing urine frequently 

You should seek help urgently if these features develop rapidly or occur together. 


As your child becomes unwell, they may become less active, sleep more and become more drowsy. More serious abnormalities are floppiness, a weak cry, irritability or poor response to things around them – see a doctor urgently if these occur.

If your child becomes unresponsive or unconscious, call Triple Zero (000). 


If your child is breathing rapidly, noisily or seems to be having difficulty breathing you should see a doctor urgently. If the problem is very severe you may see a purple colour around your child’s lips or there may be pauses when they stop breathing. You should call an ambulance if these occur.

Skin colour and appearance

If your child has unusual paleness or a purple skin on their arms and legs, you should see a doctor.

Many rashes are due to minor infections and are not serious. If your child has a purple rash that does not fade with pressure you should take them to a doctor urgently. This may be a sign of meningococcal infection. (See meningococcal fact sheet)

Fluids in and out

If your child is drinking less than half the normal amount or not passing some urine every 6 hours you should see a doctor to check if they are becoming dehydrated. Signs of serious problems include:

  • vomiting with blood or green fluid 
  • urine or stool that contains blood. 

You should see a doctor urgently if these occur. 


Fever itself is not harmful and can generally be treated at home with fluids and rest. If it is a bacterial fever, your child may be given antibiotics by your doctor.

A baby under 3 months with a fever over 38o should be taken to see a doctor as the cause is often hard to find and the other signs of illness may be difficult to detect.

Use the features described above (changes in alertness, breathing, skin colour and fluids in and out) to determine how sick an older infant or child with a fever is. If your child shivers with the fever you should take them to see a doctor.

Seizures (fits)

If your child has a seizure you should lie them on their side and call an ambulance (see seizure fact sheet).

Other signs of potentially serious problems include severe or persistent pain or distress. Contact your local doctor urgently if your child experiences these symptoms. 

The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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