The bile pigment in the human body is mainly derived from destroyed red blood cells, which are destroyed to produce hemoglobin, which is formed in the liver as indirect bilirubin and direct bilirubin. Direct bilirubin is further excreted into the intestinal cavity with bile and plays a role in digestion. After excretion into the intestinal cavity, direct bilirubin is absorbed into the body as part of the bile pigment through the hepatic-intestinal circulation. Most of the bile pigment is excreted in the urine and feces. In people with normal bile pigment, which means that the total bilirubin is within the normal range, patients have more normal bile pigment excretion and do not show elevated total bilirubin, direct bilirubin, or indirect bilirubin. If the patient has too much red blood cell destruction, excessive elevation of indirect bilirubin will develop, and the total bilirubin is usually more than 34.2umol/L or higher. If the patient has obstructive jaundice, the bilirubin level in the blood will also increase accordingly. In this case, the total bilirubin and direct bilirubin are elevated, and the total bilirubin value is also higher than 34.2umol/L or more.