The normal value of total bilirubin in liver function is between 1.7 and 17.1 umol/L. The patient’s pathological jaundice value is also known as normal bilirubin. The normal value of total bilirubin is between 1.7 and 17.1 umol/L. If the value is within this range, the patient is said to have normal bilirubin. If the patient’s total bilirubin is between 17.1 and 34.2 umol/L, the patient is said to have occult jaundice, which means that although the patient has elevated bilirubin, the patient’s skin and sclera cannot be detected by the naked eye. If the patient’s jaundice is further aggravated and the patient’s total bilirubin is above 34.2umol/L, the yellow staining of the skin and sclera can be detected by the naked eye, which is mostly called pathological jaundice. In such cases, it is necessary to combine other liver function tests to determine the cause of the jaundice. If the patient’s total bilirubin and direct bilirubin are mainly elevated, combined with elevated alkaline phosphatase and GGT, or if the patient’s upper abdominal ultrasound indicates an occupying lesion in the common bile duct, the patient is considered to have biliary obstruction causing the jaundice. In this case, the patient needs further MRI of the upper abdomen, that is, MRCP water imaging of the biliary tract, to see the cause and location of the biliary obstruction. In addition, if the patient’s total bilirubin and indirect bilirubin are mainly elevated, the patient should be considered to have hepatocellular necrosis, and the patient should actively look for the cause of the hepatocellular necrosis.