Darla Miller, age 14, of Freeport, I11., for her question:

WHAT CAUSES A JAUNDICE APPEARANCE?

Jaundice is a yellowish discoloration of the skin, the tissues and the whites of the eyes. It is not a disease, but is a symptom of various diseases.

The condition results from an increased amount of bilirubin, a reddish yellow pigment, in the blood. Bilirubin is formed by a breakdown of hemoglobin, a pigment in red blood cells.

The liver removes bilirubin from the bloodstream and secretes it in the bile. Thus, jaundice results from either excessive production of bilirubin or reduced secretion of bile.

Hemolytic jaundice results from an increased breakdown of red blood cells, which causes a greater concentration of bilirubin in the blood. Hepatocellular jaundice occurs when the liver is damaged so that it cannot secrete enough bile. Obstructive jaundice is caused by the blocking of the bile ducts.