Just high direct bilirubin indicates that there may be excessive production or impaired excretion of direct bilirubin, which is common in liver injury and obstructive diseases of the hepatobiliary tract. Direct bilirubin, also known as conjugated bilirubin, is formed when indirect bilirubin (also known as unconjugated bilirubin) is taken up by liver cells and combined with glucuronic acid. 1. Liver injury diseases: such as viral hepatitis, cirrhosis, toxic hepatitis, leptospirosis, sepsis, etc., due to severe damage to hepatocytes, its uptake of indirect bilirubin and its ability to bind bilirubin decreases, and indirect bilirubin accumulates in the blood, and undamaged hepatocytes continue to synthesize bound bilirubin, and at the same time, bile-binding bile enters into the blood through compression of the biliary ducts of the liver, which leads to an increase of bound bilirubin in the blood (direct bilirubin). 2. Biliary tract obstructive diseases: such as stones or tumors in the common bile duct, extrahepatic bile duct stones, etc. can cause direct bilirubin excretion obstacles, resulting in increased direct bilirubin in the blood. When the direct bilirubin is high, it should be diagnosed under the guidance of specialized physicians, combined with other tests, and treated actively.