The normal value of total bilirubin is 1.71~17.1μmol/l. When it reaches 400μmol/L or above, it is obviously elevated, and it is mostly considered to be caused by liver diseases, biliary tract diseases, hemolytic diseases and so on. 1. Liver diseases: such as viral hepatitis, fatty liver, liver cirrhosis, liver cancer and other diseases, which will impair the function of liver cells, affecting the metabolism of bilirubin in the liver, resulting in elevated total bilirubin. 2. Biliary tract diseases: such as cholecystitis, gallbladder stones, bile duct stones, biliary pancreatic malignant tumors and other diseases, will affect the excretion of bile to the intestines, the direct bilirubin in the bile will be absorbed into the bloodstream, resulting in increased total bilirubin. When the patient’s total bilirubin reaches 400 μmol/L or more, it is recommended to consult a doctor in time to identify the cause of the disease and carry out targeted treatment to avoid delaying the condition.