Bilirubin is a yellow bile pigment formed from the breakdown of heme in old, red blood cells. The old heme travels to the liver where it is secreted into bile by the liver and excess bilirubin is removed from the body through stool. When there are elevated levels of bilirubin in the blood serum, the eyes and skin may turn yellow or jaundice and the urine may appear a dark tea color. Elevated levels of bilirubin may be a result of excess heme breakdown or excessive reabsorption of bilirubin.
Gallstones
Elevated levels of bilirubin are consistent with obstruction of the bile ducts due to gallstones, cholangitis and choledocholithiasis. Decreased elimination of bilirubin may be caused by a gallstone or bile duct infection, known as cholangitis, leading to a blockage of the bile ducts. Choledocholithiasis is the presence of stones in the bile ducts. These stones cause biliary obstruction and bile duct infection and inflammation leading to elevated levels of bilirubin and jaundice. Gall bladder cancer also cause elevated levels of bilirubin and is clinically presented as jaundice and enlargement of the liver.
Liver Damage
Liver damage caused by hepatitis, cirrhosis due to excessive alcohol consumption or infectious mononucleosis can decrease the elimination of bilibrubin, leading to elevated bilirubin levels in blood serum. A review article by Dr. Sean Roche published in the "American Family Physician" in 2004 states that elevated serum bilirubin can be caused by acute hepatitis due to hepatitis A and hepatitis B virus. Hepatitis A viral infection usually manifests with the onset of acute jaundice while hepatitis B and hepatitis C infections can lead to progressive jaundice due to chronic infections that damage the liver. Epstein-Barr virus infections or infectious mononucleosis also cause jaundice and transient hepatitis, both of which are associated with elevated bilirubin in the serum.
Gilbert's Syndrome
Inherited conditions such as Gilbert's syndrome affect bilirubin metabolism, resulting in elevated levels of circulating bilirubin. According to the Better Health Channel from the state government of Victoria, Australia, Gilbert's syndrome is an inherited disorder that affects the breakdown of billirubin and occurs in about 5 percent of the United States population. This disorder is marked by a decrease in the activity of the enzyme glucuronosyltransfeerase, causing an increase in the bilirubin serum levels. Other than yellowing of the skin, few other symptoms are reported. Gilbert's syndrome rarely requires treatment.
