Direct bilirubin 9.0μmol/L is a mild increase, and the general reference range of direct bilirubin is 0-6.9μmol/L. Elevated direct bilirubin is commonly caused by hemolytic jaundice, hepatocellular jaundice, biliary tract obstruction, and so on. 1. Hemolytic jaundice: When a large number of red blood cells in the body are destroyed, exceeding the binding and metabolizing capacity of liver cells, and direct bilirubin accumulates in the blood, high direct bilirubin will occur. 2. Hepatocellular jaundice: pathological changes in the liver cells will lead to the weakening of their ability to synthesize and convert indirect bilirubin, and then a large amount of direct bilirubin stays in the blood, which will lead to the elevation of direct bilirubin. 3. Biliary tract obstruction: for example, biliary tract obstruction caused by biliary tract stones and biliary tract tumors, bile cannot be excreted smoothly, direct bilirubin cannot be discharged in time, and direct bilirubin will be elevated. If the direct bilirubin is 9.0 μmol/L, it is recommended to follow the doctor’s instructions for further examination, to clarify the cause with the help of the doctor, and to carry out targeted treatment or therapy. Regular medical checkups are also recommended, so that regular treatment can be given as soon as possible when abnormalities are detected.