Your baby seems off — not dramatically, just off — and you're stuck between watching a little longer and picking up the phone. First: you're not overreacting by wondering. Knowing the handful of symptoms that genuinely can't wait — and being allowed to act on a gut feeling — is one of the most useful things a parent can carry. This guide sorts the big red flags by how fast they need attention.
Go now — call an ambulance or head to emergency
Some signs mean help right away, not in the morning. Call 999 — or go straight to your nearest A&E — if your baby has any of these.
- Trouble breathing — fast or laboured breaths, grunting with each breath, the skin sucking in between or under the ribs, long pauses, or blue/grey lips, tongue or face.
- A baby you can't wake or who won't respond — floppy, limp, unusually drowsy, or staring and not engaging.
- A rash that doesn't blanch — press a clear glass firmly against the spots; if they stay visible and don't fade, this can signal a serious infection. Don't wait to see if more appear.
- A fit or seizure, repeated vomiting with a stiff neck, or a bulging soft spot.
- A fever in a baby under 3 months. Any temperature of 38°C / 100.4°F or higher in a young baby needs urgent assessment — even if they otherwise seem fine.
Call today — your GP, health visitor, or after-hours line
These don't usually mean an ambulance, but they do mean speak to someone today rather than waiting and watching.
- Signs of dehydration — far fewer wet nappies than usual, a dry mouth, no tears when crying, a sunken soft spot, or a baby who is listless and hard to rouse to feed.
- Refusing feeds repeatedly, or vomiting everything back up over several feeds.
- A fever in a baby 3–6 months, or a fever in an older baby that lasts more than two days or climbs despite simple measures.
- Persistent diarrhoea or vomiting, especially with reduced wet nappies.
- A baby who is much more unsettled or much quieter than their normal self.
| Wet nappies (rough guide) | What it usually means |
|---|---|
| 6–8 heavy/day after the first week | Well hydrated |
| Noticeably fewer than usual | Watch closely, offer feeds, ring if it continues |
| Very few or none in 6–8+ hours | Urgent — call today |
Wet-nappy counts are a guide, not a diagnosis. Australia's Raising Children Network, the AAP (US) and WHO all point to the same core danger signs above — trouble breathing, poor feeding, lethargy, fever in a young baby — and the thresholds are broadly consistent across regions, though who you ring first differs by region: for advice, NHS 111.
Trust your gut
You don't need a textbook symptom to justify a call. Parents notice subtle changes — a different cry, an unusual stillness, a feeling that "this isn't right" — long before a number on a thermometer confirms it. Clinicians take parental instinct seriously, and so should you.
If in doubt about anything in this guide, your GP, health visitor, or local health line is always the right call — that's exactly what they're there for, at any hour.
This guide is general information, not medical advice, and can't diagnose your baby. When something worries you, contact your doctor, health visitor, or emergency services.