Indirect bilirubin is converted from hemoglobin after the destruction of red blood cells and reflects the conversion function of hepatocytes and the catabolic state of red blood cells. Direct bilirubin is produced from indirect bilirubin entering the liver and combining with glucuronide by the action of glucuronosyltransferase in the liver, reflecting the excretion of bilirubin from the bile. Total bilirubin is composed of direct bilirubin and indirect bilirubin. Currently, total bilirubin, direct bilirubin and indirect bilirubin are important indicators of liver function by which the diagnosis of jaundice and the differential diagnosis of specific types can be facilitated. Patients with hemolytic jaundice are mainly characterized by elevated total and indirect bilirubin. In patients with obstructive jaundice, total bilirubin and direct bilirubin are predominantly elevated. In hepatocellular jaundice, all three values are more significantly elevated.