The 8 ‘red flags’ for unwell babies and children.

Last updated: June 2026

When your little one is unwell at 3 am, it can be hard to know what’s “just a bug” and what needs urgent medical attention.

That’s where red flags come in. These are the really concerning signs and symptoms that tell you it’s time to seek urgent medical help – no waiting, no second-guessing.

As parents and carers, we often know the “cut and dry” emergencies – a serious burn, a deep cut, a child who is unconscious. But when little ones are generally unwell, it can feel harder to judge. These 8 red flags will help.

The information below comes from the Sydney Children’s Hospital Network ‘Signs of Serious Illness in Children‘ fact sheet and, in particular, the ‘Recognising serious illness in children‘ checklist. 

We recommend downloading the checklist; it’s a free and incredibly valuable resource!

Here are our 8 ‘red flags’ for the unwell baby or child:

1. Abnormal or distressed breathing

This is a big one. Signs of breathing difficulty include:

• Breathing faster than normal 
• Nostrils flaring, head bobbing
• Sucking in under the rib cage or at the front of the neck, tummy “see-sawing”
• Abnormal breathing sounds
• Breathlessness
• Unable to say more than a few words at once (for children who normally talk)
• Breathing that pauses for more than 10 seconds

There can be many reasons a child is struggling to breathe or breathing faster than normal – but regardless of the cause, this is a red flag – call 000 or go to your nearest emergency department

We know descriptions only go so far, and seeing it can help. WATCH: What breathing difficulties can look like

2. Not feeding properly (especially babies)

One of the first things you may notice when your child becomes unwell is that they’re refusing or not wanting their feeds. Babies can become dehydrated very quickly. If feeding has dropped off significantly or they’re refusing to feed, that’s a red flag – and in babies under 1 month old, no interest in feeding at all needs urgent medical attention.

In older babies and children, watch for: not drinking for more than 8 hours (while awake), being extremely thirsty, or being unable to keep fluids down.

3. Fewer wet nappies than usual

Not producing enough urine is concerning. If your child is unwell and has had no wee or wet nappy for 8 hours, or you’re seeing fewer wet nappies or toilet trips than usual, dark urine, dry lips or tongue, sunken eyes, see a doctor – they may be dehydrated.

And if your child has bloody, black, brown or dark green vomit, or very bloody or black poo, that’s a medical emergency –  go to your nearest emergency department.

4. Not alert, can’t awaken, or unable to be consoled

Is bub floppy? Can they be easily roused? If your little one is lethargic and drowsy when it isn’t their normal sleep time, won’t stay awake, doesn’t seem to recognise you, or is unresponsive, they need urgent medical attention. Call 000 ambulance.

The same goes for a weak cry, an absent cry, or a high-pitched continuous cry in a baby who is unusually unsettled and can’t be consoled, or if they have severe or unexplained pain.

In older children, confusion is also a red flag.

Call 000 if your child has a seizure.

5. A rash that doesn’t fade when pressed (non-blanching rash)

If a purple or red rash doesn’t disappear when pressed firmly, it’s called a non-blanching rash. It can be a sign of serious illness (you’ve probably heard of meningococcal infection, but there are other causes too) and needs urgent medical attention.
You can check at home using the glass test: press a clear glass firmly against the rash and see if it fades.
Important: In most cases, you’ll see other red flags before a rash like this appears – don’t wait for a rash if you’re seeing other red flags.
Any other rash with a fever? Take your child to see your GP. 

Know how to check: the glass test takes 10 seconds. WATCH: Our glass test demonstration

6. A baby under 3 months with a temperature of 38°C or higher

NOTE: (Corrected age if premature)
In older children, we look at the whole child – not just the number on the thermometer. But in babies aged 0–3 months, a temperature of 38°C or higher is an automatic trip to the hospital, even if they’re showing no other signs of being sick. No exceptions.

7. Unusual skin colour or appearance

A change from their normal skin colour is a red flag:

• Sudden tongue swelling – this is a medical emergency.
• Blue (on their lips, tongue, torso, nail beds) – this is a medical emergency.
• Very pale or grey compared to their usual colour.
• Mottled skin, if your child isn’t normally like that. Note that mottling can be normal for babies and for some children, but you know what’s “normal” for your child better than anyone. Remember that!
• Hands and feet are unusually cold to the touch.

8. YOUR GUT INSTINCT TELLING YOU THAT SOMETHING IS WRONG

This one’s in capitals for a reason – because it is so, so important.

If your gut is telling you something is wrong, TRUST it and ACT on it. Don’t underestimate your ability to pick up that something isn’t right with your child and that they need urgent medical attention. You know your child best.

You never have to wait for breathing distress to become severe or prominent before seeking help. Any changes in breathing, even just faster than their normal, are worth acting on. And always trust your gut. You know your child better than anyone.

Final reminder…

Remember: most winter illnesses are mild and manageable at home. Knowing the red flags isn’t about panic; it’s about confidence. When you know what to look for, you can trust yourself to act when it matters.

And if you’re ever unsure? Seeking help is always the right call. No one will ever think you’re overreacting – that’s what medical professionals are there for. Call 000 ambulance for emergencies, and 1800MEDICARE Australia wide to speak to a Registered Nurse for health advice, especially if you are unsure what to do. 

The above information comes from the Sydney Children’s Hospital Network ‘Signs of Serious Illness in Children‘ fact sheet and, in particular, the ‘Recognising serious illness in children‘ checklist. We recommend downloading this; it’s free and an incredibly valuable resource!