For patients, the normal human bilirubin is usually between 1.7-17μmol/L. If the patient’s total bilirubin exceeds 17.1 μmol/L, between 17.1-34.2 μmol/L, then the patient is considered to have hidden jaundice. This means that if the patient’s blood jaundice is slightly elevated, but the yellowing of the patient’s skin and sclera cannot be detected by the naked eye. If the patient’s bilirubin is further elevated, with a total bilirubin of more than 34.2 μmol/L, the patient is said to be jaundiced, i.e., the yellowing of the skin and sclera can be detected with the naked eye. In such cases, it is necessary to identify whether the patient is suffering from obstruction or due to hepatocellular necrosis. If direct bilirubin is predominantly elevated, then obstructive factors are considered to be predominant. If indirect bilirubin is predominantly elevated, jaundice may be caused by hepatocellular necrosis. Different causes of jaundice require different treatment.