What is jaundice?
Jaundice is a yellow color of the skin and the whites of the eyes that's caused by the buildup of bilirubin in the blood. Bilirubin is a yellow substance your body makes when it breaks down red blood cells. A lot of bilirubin in the blood causes the skin and the white parts of the eye to turn yellow.
Jaundice is common in newborn babies. (Adults can get jaundice too, see Jaundice in Adults Jaundice in Adults Jaundice is a yellow color to your skin and the whites of your eyes. Jaundice is caused by a buildup of a substance called bilirubin Bilirubin is a yellow substance your body makes when it breaks... read more 
).
Jaundice happens when a newborn has too much bilirubin in the blood
Usually, mild jaundice happens 2 or 3 days after birth and goes away on its own within 2 weeks
Jaundice is common in newborns because they make more bilirubin than adults and have a harder time getting rid of it
Jaundice has many causes, some are serious and some are minor
Whatever the cause of jaundice, very high levels of bilirubin can harm your baby's brain
What causes jaundice in newborns?
The most common causes of jaundice in newborns are:
Normal development: Your baby's liver is still growing and doesn't get rid of bilirubin well—this jaundice usually gets better within a week
Prematurity: Your baby was premature Premature Baby A premature baby is born too early. A full pregnancy lasts 37 to 40 weeks, so a premature baby is born anytime before the 37th week of pregnancy. The more premature babies are, the more likely... read more , born before week 37 of your pregnancy
Breastfeeding: Your baby has trouble breastfeeding and isn't getting enough milk (breastfeeding jaundice)
Breast milk: Your breast milk has high levels of a substance that makes your baby's bilirubin level go up (breast milk jaundice)
Injury: Your baby had an injury during birth that caused bleeding under the skin (hematoma) and then breakdown of the blood in the skin raised the bilirubin level
Less common causes of jaundice in newborns are:
Mismatch between the mother's and baby's blood types
Inherited problems with the baby's red blood cells or liver
Blockage of the tube that drains fluid from the liver into the intestine
Underactive thyroid gland (a gland that helps regulate many things in the body)
When should my baby see a doctor for jaundice?
If you deliver your baby in the hospital, doctors and nurses will check your baby for jaundice. If your baby is at home, go to the hospital if your baby's eyes or skin look yellow and your baby has any of these warning signs:
The yellow skin or eye color happened in the first day after birth
Your baby is 2 weeks old or older
Your baby doesn't eat well, is fussy, and has trouble breathing
Your baby has a fever
If your baby has yellow skin and eyes but no warning signs, call your baby's doctor.
With severe jaundice, bilirubin builds up in the baby's brain and causes brain damage. Such brain damage is rare, but the chances are higher if your baby is premature.
How can doctors tell if my baby has jaundice?
Doctors look at your baby's skin and eyes for a yellow color. They'll test your baby's bilirubin level by:
Doing a blood test
Putting a sensor on the baby's skin
To see what’s causing your baby's jaundice, doctors may do:
Blood tests
Urine tests
How do doctors treat jaundice in newborns?
Doctors will treat the cause of jaundice in your baby. Mild jaundice may not need treatment.
Doctors may have you:
Feed your baby more often, so your baby poops more often (this helps bilirubin leave your baby's body)
Pump rather than breastfeed for a day or two, if your baby has breast milk jaundice
If your baby has a very high bilirubin level, doctors may do:
Phototherapy (a bright, blue light is shined on your baby's skin to help break down the bilirubin)
Blood tests for a few days to check that the baby's bilirubin levels are going down
If phototherapy doesn't work, doctors may do:
A special type of blood transfusion called an exchange transfusion
With an exchange transfusion, a small amount of your baby's blood is taken out and replaced with donor blood. The donor blood has a normal level of bilirubin.
