A yellow tinge to a newborn’s skin and the whites of their eyes — jaundice — is one of the most common things in the early days. Most babies get at least a little, and the great majority of the time it’s harmless and clears on its own. Because it can occasionally signal something that needs treatment, though, it’s worth understanding what’s normal, how it’s checked, and the few signs that mean get it looked at. Here’s the plain-language picture.
Why newborns get jaundice
Jaundice is caused by a build-up of bilirubin, a yellow substance made when the body breaks down red blood cells — something newborns do a lot of. Their liver, which clears bilirubin, is still immature and works slowly at first, so it builds up faster than it’s removed. That combination is why jaundice is so common in the first days. Most of the time this is physiological jaundice — the normal, passing kind.
What normal jaundice looks like
Typical, harmless jaundice:
- Appears around day two or three — not in the first 24 hours.
- Peaks by about day five, then fades by around two weeks.
- Starts on the face and moves down the body as it increases.
- Happens in a baby who is otherwise feeding well, alert, and having plenty of wet and dirty nappies.
In breastfed babies it can linger a little longer (sometimes called breast milk jaundice), which is usually still harmless — but jaundice that’s still there after two weeks should always be checked.
How it’s checked and treated
At your newborn checks and home visits, a midwife or doctor looks for jaundice and, if needed, measures it with a light meter on the skin or a small blood test (a heel prick). Most jaundice needs no treatment and simply fades. Because bilirubin leaves the body in wee and poo, feeding frequently helps clear it, so keep feeds up.
If a test shows the level is high, the usual treatment is phototherapy — your baby lies under a special blue light in hospital that helps break the bilirubin down. It’s very effective, and with monitoring and treatment when needed, serious problems are rare.
When to get it checked
Though usually harmless, get advice promptly if:
| Usually normal | Get it checked |
|---|---|
| Appears day 2–3, fades by ~2 weeks | Appears in the first 24 hours |
| Baby feeding well, alert, plenty of nappies | Baby sleepy, floppy, or feeding poorly |
| Mild yellow on the face and chest | Deepening, or yellow down to the legs |
| (Breastfed: may linger a little longer) | Pale, chalky stools and dark urine, or still there after 2 weeks |
The last one matters: jaundice with pale stools and dark urine can point to a liver problem and needs checking — it’s one reason the colour of your baby’s nappies is worth a glance. As with anything in the early weeks, if your instinct says something’s wrong, get your baby seen.
The short version
Newborn jaundice is usually just a newborn liver catching up, and it passes on its own while your midwife keeps an eye on it at your checks. Keep feeding well, watch for the handful of red flags above — early onset, deepening, poor feeding, pale stools, or lasting beyond two weeks — and let the professionals monitor and treat it if it’s ever needed. Most of the time, the yellow simply fades.
This is general information, not medical advice. Jaundice is monitored and, if needed, treated by health professionals — follow the advice of your midwife, health visitor, or doctor, and seek prompt help for any of the red flags above.