Bile acids are the major organic component in bile. They are amphipathic, derived from cholesterol synthesized in the hepatocyte. Their amphipathic nature enables them to carry out two important functions: emulsification of lipid aggregates, and solubilization and transport of lipids in an aqueous environment. Hepatic synthesis of bile acids accounts for the majority of cholesterol breakdown in the body. This route for elimination of excess cholesterol is particularly important in situations of massive cholesterol ingestion. Bile acids are also involved in apoptosis, mucin secretion, and biliary ductular secretion. ELEVATED levels are associated with hepatic neoplasia, portosystemic shunt, hepatic lipidosis, hepatitis, bile duct obstruction, copper toxicity, and almost any condition that causes a defect in hepatic uptake or portal circulation.