The normal value of bilirubin is total bilirubin, 1.71 to 17.1 millimoles per liter, where direct bilirubin is 1.71-7 millimoles per liter and indirect bilirubin is 1.71-13.7 millimoles per liter, that is, total bilirubin is the sum of indirect bilirubin plus direct bilirubin, of course, the reference value varies from place to place The normal value of bilirubin should be determined according to the reference value of the examination institution. Bilirubin is the main pigment in human bile, its color is yellow, bile pigment in the body and iron porphyrins combined with chemical reactions to become red, so also known as bilirubin, too much bilirubin gathered in the body, will produce a certain degree of toxicity, especially for the nervous system has irreversible damage, but also pay attention to the damage to the brain. Elevated bilirubin should be considered caused by liver disease, such as hepatocellular jaundice, and obstructive jaundice, such as cholangitis, bile duct stones, bile duct malignancies, etc., which may lead to the occurrence of obstructive jaundice, and some belong to hemolytic jaundice, especially to pay attention to transfusion reactions, blood diseases, and some newborns may also appear physiological jaundice or pathological jaundice. All of these diseases may lead to an increase in bilirubin. If a patient’s bilirubin test shows that the total bilirubin, direct bilirubin, and indirect bilirubin exceed normal values, it is important to promptly investigate and treat the cause of the elevated bilirubin.