The causes of high direct bilirubin include intra- and extra-hepatic obstruction and non-hepatobiliary diseases. 1. Intra- and extra-hepatic obstruction: intra- and extra-hepatic obstruction caused by obstructive jaundice, capillary hepatitis, cholestasis syndrome, etc., which leads to obstruction of bile excretion pathway, poor excretion and bile siltation, resulting in elevated pressure in the bile ducts, rupture of capillary bile ducts, and the emergence of direct bilirubin in bile into the blood, which leads to a significant increase in direct bilirubin in the blood. 2. Non-hepatic and biliary diseases: mainly include liver function injury caused by many other diseases, tumors in duodenal jugular abdomen, pancreatic head cancer, pancreatic tumors, etc. At the beginning, the symptoms are not obvious, but with the progression of the disease, the bile ducts are compressed and bile discharge is affected, which leads to the elevation of direct bilirubin. High direct bilirubin alone can not accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.