Bile acids can check the body for hepatocellular damage, biliary obstruction, and portal shunt. Bile acid is one of the main components of bile. Hepatocytes use cholesterol as raw material to synthesize primary bile acid directly, and then it enters into the intestine with bile to be transformed into secondary bile acid, and most of the bile acid is reabsorbed at the end of the ileum and enters into the liver through the portal vein, and then it is recycled and utilized. 1. Hepatocellular injury: when hepatocellular injury is caused by various reasons, such as acute hepatitis, chronic active hepatitis, cirrhosis, hepatocellular carcinoma, alcoholic liver, etc., bile acids already synthesized in the liver can be released into the bloodstream due to hepatocellular injury, which will lead to the elevation of bile acid level. 2. Bile duct obstruction: When bile duct obstruction is caused by stone blockage or tumor compression, bile acids cannot enter the intestinal cavity smoothly, and the pressure in the bile duct rises and causes bile acids to seep into the blood circulation, which can also lead to an increase in bile acid level. 3. Portal vein shunt: If the patient has a portal vein shunt, the secondary bile acids in the intestines may enter the blood circulation directly through the shunted portal vein due to reabsorption, which may cause the bile acid level to rise. Serum bile acids may rise transiently in healthy people after eating, so patients with elevated bile acids do not need to worry too much, and it is recommended that they actively seek medical attention to identify the cause of the elevation and then deal with it accordingly.