Marker of liver and biliary tract dysfunction

Bilirubin is one of the main components of bile and is formed during the metabolism of hemoglobin. Other sources of bilirubin may include myoglobin, cytochromes, and other heme-containing pigments. During the breakdown of hemoglobin, free (indirect) bilirubin is first formed. Free bilirubin is transported from the spleen to the liver in combination with albumin.