Causes of Elevations in Indirect and Direct Bilirubin Levels
| Increased Indirect (Unconjugated) Bilirubin | Increased Direct (Conjugated) Bilirubin |
|---|---|
| Hemolysis: hemoglobinopathies, spherocytosis, G-6-PD deficiency, autoimmunity, transfusion reaction Red blood cell degradation: hemorrhage into soft tissues or body cavities, inefficient erythropoiesis, pernicious anemia Defective hepatocellular uptake or conjugation: viral hepatitis, hereditary enzyme deficiencies (Gilbert, Crigler-Najjar syndromes), hepatic immaturity in newborns | Intrahepatic disruption: viral hepatitis, alcoholic hepatitis, chlorpromazine, cirrhosis Bile duct disease: biliary cirrhosis, cholangitis (idiopathic, infectious), biliary atresiaa Extrahepatic bile duct obstruction: gallstones; carcinoma of gallbladder, bile ducts, or head of pancreas; bile duct stricture from inflammation or surgical misadventure |