Clinically, jaundice is divided into three types: the first is prehepatic; the second is hepatocellular; and the third is posthepatic. Prehepatic jaundice is mainly due to hemolysis and develops not in the liver, but in the prehepatic area. Hepatocellular jaundice, which is jaundice due to disease of the liver itself, is most commonly caused by hepatitis and other causes of liver injury. In hepatocellular jaundice, it is characterized by a direct bilirubin of 30%-50% of the total bilirubin, along with liver function impairment, and then further tests reveal hepatitis B or C and abnormal liver density on ultrasound. Post-hepatic jaundice is commonly associated with obstructive jaundice, caused by intrahepatic obstruction or extrahepatic bile duct obstruction, and the proportion of direct bilirubin to total bilirubin in this jaundice is higher than about 60%. Clinically common jaundice is mostly seen in gastroenterology as hepatocellular jaundice.