Causes of Elevated Direct Bilirubin

Direct bilirubin refers to the unconjugated bilirubin in the blood and is closely related to liver function. When direct bilirubin levels increase, it usually indicates an abnormality in the liver or biliary system. 1. Liver diseases: Conditions such as hepatitis, cirrhosis, and liver tumors can cause disturbances in bilirubin metabolism, leading to elevated levels of direct bilirubin. When liver cells are damaged or liver function is impaired, the excretion of bilirubin decreases, resulting in increased concentrations of direct bilirubin. 2. Biliary obstruction: Gallstones, bile duct tumors, or bile duct strictures can block the excretion of bile, preventing bilirubin from being normally eliminated from the body. This leads to accumulation of bilirubin in the blood and elevated direct bilirubin levels. 3. Hemolytic diseases: Although increases in direct bilirubin are not as commonly seen in hemolytic anemia as increases in indirect bilirubin, excessive bilirubin caused by hemolytic disorders may also affect direct bilirubin levels to some extent. Note that the specific cause of elevated direct bilirubin should be determined through further examinations, such as liver function tests and imaging studies.