Indirect bilirubin of 19.5 umol/L is on the high side. The causes of elevation include physiological causes such as fatigue and strenuous exercise; pathological causes such as hepatitis, cholelithiasis and other liver and biliary system diseases; hemolytic anemia and other blood system diseases; lead poisoning, blood group incompatibility transfusion and so on. 1. Physiological causes: fatigue, strenuous exercise and other factors may lead to a transient increase in indirect bilirubin. 2. Pathologic causes: (1) Hepatobiliary system diseases: Hepatitis, cirrhosis and other liver diseases may lead to elevated hepatocellular indirect bilirubin; biliary system diseases such as cholelithiasis, intrahepatic bile duct stone disease are also causes of elevated indirect bilirubin. (2) Hematologic diseases, such as hemolytic anemia and dysproteinemic anemia, require prompt consultation with a hematologist. (3) Other causes: such as lead poisoning, blood group dyscrasia and blood transfusion, which are common in patients with a history of blood transfusion and lead exposure. Indirect bilirubin elevation may also have other causes, it is recommended to go to the hospital in a timely manner to improve the examination, identify the cause of the disease and then give targeted treatment.