Red flags — seek same-day medical review if:
- Jaundice appears within the first 24 hours of life.
- The baby looks yellow on the legs, feet, or palms, not just the face.
- The baby is feeding poorly, unusually sleepy, or hard to wake for feeds.
- The baby has fewer wet nappies than expected or pale, chalky stools.
- Jaundice is still present or worsening after two to three weeks of age.
If your baby has a fever, remember: fever of 38°C or more in a baby under 3 months is an emergency — do not give paracetamol and wait; seek urgent medical care.
Why it happens
Almost every baby has some yellowing of the skin and eyes in the first week of life, and it is one of the most normal things a newborn body does. Before birth, a baby needs a lot of red blood cells to carry oxygen efficiently in the womb. After birth, the baby breathes air directly and no longer needs so many red cells, so the body starts breaking the extra ones down. That breakdown produces a yellow pigment called bilirubin. A newborn's liver is still learning its job, and it processes bilirubin more slowly than an adult's liver does. While the liver catches up, bilirubin builds up a little in the blood and shows in the skin and the whites of the eyes as a yellow tint. This is called physiological jaundice, and it is the most common form.
A smaller number of babies become yellow because they are not yet feeding often or effectively enough, which slows down how quickly bilirubin leaves the body through stools. This is sometimes called breastfeeding-associated jaundice, and it usually improves once feeding is well established. A different and less common pattern is jaundice that appears in the first 24 hours of life, which behaves differently and is taken more seriously because it can point to the baby's red cells breaking down faster than usual, for example due to a blood group mismatch between mother and baby.
What you will notice
Jaundice usually starts on the face and forehead and, if it increases, spreads downward toward the chest, tummy, and eventually the legs and feet. The whites of the eyes may look yellow too. It tends to become most visible around day 3 to day 5 of life and then fade gradually over one to two weeks. Checking in natural daylight, rather than under artificial light, gives a truer picture of the baby's colour. Gently pressing a fingertip on the skin and watching the colour that shows as you release the pressure can help you see the tint more clearly, especially on lighter skin. On deeper skin tones, the yellow tinge is easier to see in the whites of the eyes, the gums, and the palms and soles.
What to do
Keep feeding often and on demand; frequent feeding is one of the most effective ways to help a newborn clear bilirubin, because it keeps the bowels moving. Watch the number and colour of wet and dirty nappies as a sign that feeding is going well (see the separate page on nappy output). Most babies with mild jaundice need nothing more than good feeding and time, but any baby who is noticeably yellow should still be checked by a midwife, health visitor, or doctor, because only a blood or skin test can tell how high the bilirubin level actually is — looking at skin colour alone cannot measure it.
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Message us on WhatsAppClinical thresholds in this page were reviewed and signed off by Dr Didier Decamps on 17 August 2026. This is general information and does not replace an individual assessment by a qualified clinician.
Written with AI assistance. Reviewed, corrected and signed by Dr Didier Decamps, paediatrician.
Last reviewed: 17 August 2026