Jaundice

What is jaundice?

Jaundice is a yellowing of the skin, whites of the eyes, and body fluids. It is caused by an increase in the amount of bilirubin in the blood. Bilirubin is a yellowish pigment that is produced from the breakdown of heme, primarily from hemoglobin and red blood cells (RBCs). Bilirubin is transported by the blood to the liver, where the liver processes it, allowing it to be excreted in bile. Bile is a thick, yellow-green-brown fluid that is secreted into the upper small intestine (duodenum) to get rid of waste products (such as bilirubin and excess cholesterol) and to aid in the digestion of fats. Jaundice may arise from increased breakdown of red blood cells, inherited changes in bilirubin metabolism, liver disease or damage, and whenever there is interference with bile excretion.

Examples of common conditions that may cause jaundice

• Acute hepatitis: liver inflammation due to a variety of causes including hepatitis A, B, C, D, and E viral infections, alcohol abuse, and some medications and toxins.
• Obstruction of the bile ducts inside and/or outside of the liver: may be due to a stone, damage and scarring, or biliary atresia, a congenital condition associated with abnormal development or the bile ducts. It leads to the back-up and pooling of the bile behind the obstruction and to the increase of bilirubin in the blood. Gallstones can block bile ducts and pancreatic cancer can sometimes lead to a blockage in the bile ducts outside of the liver.
• Hemolytic anemia: an abnormal hemoglobin variant, malaria, an autoimmune process, hemolytic disease of the newborn, and any other conditions that lead to a significant increase in the destruction of red blood cells and to an increase in the production of bilirubin.
• Gilbert's syndrome: a mild inherited condition associated with decreased bilirubin conjugation due to a decrease in enzyme activity. Those affected may have temporary jaundice during times of illness or stress and increases in their unconjugated bilirubin levels.
• Cirrhosis: can cause jaundice in its late stages.
• Physiologic jaundice of the newborn: the liver of a newborn infant has not fully developed its ability to metabolize bilirubin yet, so newborns frequently go through a brief period of jaundice right after they are born. Newborns with jaundice are carefully monitored and generally improve within 48 to 72 hours. If the jaundice persists or is severe, however, the infant may be treated and evaluated for other causes (such as hemolytic disease of the newborn).

Examples of more rare conditions that may cause jaundice

• Crigler-Najjar syndrome: an inherited condition that may lead to severe unconjugated hyperbilirubinemia (high bilirubin concentrations); a gene mutation leads to a deficiency in an enzyme necessary for bilirubin conjugation.
• Dubin-Johnson syndrome: an inherited disorder that causes the retention of conjugated bilirubin (and other compounds that turn the liver black) in liver cells; patients may have intermittent jaundice.
• Rotor’s syndrome: an inherited conjugated hyperbilirubinemia that causes intermittent jaundice; similar to Dubin-Johnson without the retention of other compounds or a black liver.
• Pseudojaundice: the skin of a person may turn yellowish when they eat large quantities of carrots, squash, or cantaloupe due to the presence of beta-carotene; this is a temporary and benign condition that is not related to bilirubin or bile.