Jaundice in the adult patient.

Jaundice in an adult patient can be caused by a wide variety of benign or life-threatening disorders. Organizing the differential diagnosis by prehepatic, intrahepatic, and posthepatic causes may help make the work-up more manageable. Prehepatic causes of jaundice include hemolysis and hematoma resorption, which lead to elevated levels of unconjugated (indirect) bilirubin. Intrahepatic disorders can lead to unconjugated or conjugated hyperbilirubinemia. The conjugated (direct) bilirubin level is often elevated by alcohol, infectious hepatitis, drug reactions, and autoimmune disorders. Posthepatic disorders also can cause conjugated hyperbilirubinemia. Gallstone formation is the most common and benign posthepatic process that causes jaundice; however, the differential diagnosis also includes serious conditions such as biliary tract infection, pancreatitis, and malignancies. The laboratory work-up should begin with a urine test for bilirubin, which indicates that conjugated hyperbilirubinemia is present. If the complete blood count and initial tests for liver function and infectious hepatitis are unrevealing, the work-up typically proceeds to abdominal imaging by ultrasonography or computed tomographic scanning. In a few instances, more invasive procedures such as cholangiography or liver biopsy may be needed to arrive at a diagnosis.