Jaundice is a yellow discoloration that affects the skin, whites of the eyes and mucous membranes (e.g., inside the mouth). Although jaundice is not typically dangerous in itself, it may signify the presence of an underlying condition. For example, jaundice is a common sign of advanced liver disease. Typically, jaundice develops after a condition has been present for a while. Other symptoms of the disorder tend to occur before jaundice is noticeable.

Jaundice is the deposition of pigments in the skin that results from high levels of the yellow pigment bilirubin in the blood. Bilirubin is a product of the natural breakdown of red blood cells. The bloodstream carries the bilirubin to the liver, where it is processed and used as a component of bile. The bile is either secreted through bile ducts directly into the small intestine to help with digestion or stored in the gallbladder until it is needed. Some of the bile that has been secreted into the intestines is reabsorbed. Much of the bilirubin, however, is eliminated from the body through bowel movements. If bilirubin is not properly eliminated from the body, it builds up in the blood and body tissues, resulting in jaundice. In addition to jaundice, high levels of bilirubin in the blood can also cause generalized itchiness (pruritus).

Jaundice may result from liver conditions such as hepatitis and cirrhosis. Obstruction of the bile ducts (often caused by gallstones) can also cause jaundice.

Jaundice is common in newborn infants. The newborn liver is often not mature enough to process bilirubin. Because the liver is overwhelmed, bilirubin is not removed from the bloodstream fast enough and is deposited in the tissues of the body. In most cases, infant jaundice causes no harm and goes away in a week or two. However, it must still be monitored because it can progress to severe jaundice with serious complications.