"Physiologic jaundice" is an indicator that a baby's blood contains an excess amount of bilirubin, a chemical formed during the normal breakdown of old red blood cells. We all have some bilirubin in our blood, but newborns usually have higher levels because their young immune system takes longer to process the extra red blood cells present at birth. Signs: A yellowish tint to the skin that usually appears first on the face and then on the chest, abdomen, and legs. To test, gently press on your baby's nose, forehead, or thigh to see if the skin beneath your finger appears yellow. Treatment: Jaundice usually corrects itself within a few days (though it may worsen before it gets better). If it doesn't, you child's pediatrician may do a blood test to determine the bilirubin level. If the level is extremely high and goes untreated, there is a chance that damage to the nervous system can occur. Your doctor may recommend phototherapy -- a treatment in which your baby is placed under special fluorescent-type lights for a day or two.