Your baby will have a visual examination to look for signs of jaundice.
They need to be undressed during this so their skin can be looked at under good, preferably natural, light.
Other things that may also be checked include:
- the whites of your baby's eyes
- your baby's gums
- the colour of your baby's urine or poo
If it's thought your baby has jaundice, the level of bilirubin in their blood will need to be tested.
This can be done using:
- a small device called a bilirubinometer, which shines light on to your baby's skin (it calculates the level of bilirubin by analysing how the light reflects off or is absorbed by the skin)
- a blood test of a sample of blood taken by pricking your baby's heel with a needle (the level of bilirubin in the liquid part of the blood called the serum is then measured)
In most cases, a bilirubinometer is used to check for jaundice in babies.
Blood tests are usually only necessary if your baby developed jaundice within 24 hours of birth or the reading is particularly high.
The level of bilirubin detected in your baby's blood is used to decide whether any treatment is needed.
Read more about treating jaundice in babies.
Further blood tests may be needed if your baby's jaundice lasts longer than 2 weeks or treatment is needed.
The blood is analysed to determine:
- the baby's blood group (this is to see if it's incompatible with the mother's)
- whether any antibodies (infection-fighting proteins) are attached to the baby's red blood cells
- the number of cells in the baby's blood
- whether there's any infection
- whether there's an enzyme deficiency
These tests help determine whether there's an underlying cause for the raised levels of bilirubin.