Over half of all newborns develop some amount of jaundice, a yellow coloring in their skin, during the first week of life. This is usually temporary, but could be a sign of a more serious illness.
Jaundice is caused by the breakdown of red blood cells. Bilirubin is made during this process and removed by the liver. Too much bilirubin in the blood is called hyperbilirubinemia. Bilirubin has a yellow color and causes a yellowing of the baby's skin and tissues.
As liver function matures, the jaundice goes away.