Jaundice

Jaundice is not a disease but rather a sign that can occur in many different diseases. Jaundice is the yellowish staining of the skin and sclerae (the whites of the eyes) that is caused by high levels in blood of the chemical bilirubin. The color of the skin and sclerae vary depending on the level of bilirubin. When the bilirubin level is mildly elevated, they are yellowish. When the bilirubin level is high, they tend to be brown.

Bilirubin comes from red blood cells. When red blood cells get old, they are destroyed. Hemoglobin, the iron-containing chemical in red blood cells that carries oxygen, is released from the destroyed red blood cells after the iron it contains is removed. The chemical that remains in the blood after the iron is removed becomes bilirubin.

Neonatal jaundice is jaundice that begins within the first few days after birth. (Jaundice that is present at the time of birth suggests a more serious cause of the jaundice.) In fact, bilirubin levels in the blood become elevated in almost all infants during the first few days following birth, and jaundice occurs in more than half. For all but a few infants, the elevation and jaundice represents a normal physiological phenomenon and does not cause problems.