What is jaundice?
Jaundice, also known as icterus, is a yellowing of the skin, whites of the eyes, and body fluids due to an increase in the amount of bilirubin in the blood. Bilirubin is a yellowish pigment and byproduct of the natural daily breakdown of red blood cells (RBCs). Red blood cells typically survive for about 120 days and then are broken down by the body, forming bilirubin in the process. Bilirubin is transported by the blood to the liver, where it is metabolized and excreted in the bile, a thick, yellow-green-brown fluid that is secreted into the upper small intestine (duodenum) to eliminate waste products (such as bilirubin and excess cholesterol) and to aid in the digestion of fats. Jaundice may result from a disruption in this normal metabolism and/or the overproduction of bilirubin.
Jaundice is not an illness but a medical condition or sign of an underlying problem with the liver, pancreas, or gallbladder. Infections, use of certain drugs, cancer, blood disorders, gallstones, birth defects, inherited conditions, and a number of other medical conditions can result in jaundice. In general, the causes of jaundice may fall into one of three main categories:
- Conditions caused by the liver's inability to properly metabolize and excrete bilirubin
- Conditions that result in shortened survival of red blood cells, which in turn increases the level of bilirubin
- Conditions that prevent elimination of bilirubin from the body
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 (e.g., acetaminophen) and toxins
- Conditions caused by obstruction of the bile ducts such as damage and scarring or biliary atresia, a congenital condition associated with abnormal development of the bile ducts that leads to the backup and pooling of the bile and to the increase of bilirubin in the blood. Gallstones as well as pancreatic cancer can sometimes lead to a blockage in the bile ducts.
- Conditions that lead to a significant increase in the destruction of red blood cells and to an increase in the production of bilirubin, such as hemolytic anemia, due to an abnormal hemoglobin variant, malaria, autoimmune disorder, or hemolytic disease of the newborn (HDN).
- Gilbert syndrome: a mild inherited condition associated with decreased bilirubin metabolism 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 yet developed its ability to metabolize bilirubin, 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 and more severe conditions, 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; those affected may have intermittent jaundice.
- Rotor syndrome: an inherited conjugated hyperbilirubinemia that causes intermittent jaundice; similar to Dubin-Johnson without the retention of other compounds or a black liver.
- The drug atazanavir (sometimes used to treat HIV infection) causes the same block in bilirubin metabolism as Gilbert syndrome and can cause mild jaundice that can worsen at times of illness or stress.
- 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.