Checking liver function requires testing liver synthetic function indicators such as serum protein, liver cell damage indicators such as transaminases, bilirubin metabolism and other tests. 1. Liver synthesis function: (1) Serum serum protein: serum protein is only synthesized by hepatocytes, and when the synthesis function of the liver is reduced to a certain degree, serum serum protein will be significantly reduced. (2) Plasma coagulation factors: most of the coagulation factors are synthesized in the liver, so there will be some changes in coagulation function when liver function is impaired. (3) Cholesterol: about 70% of endogenous cholesterol is synthesized in the liver, and blood cholesterol levels will decrease when hepatic synthesis is impaired. 2. Hepatocellular damage: alanine aminotransferase (ALT) and aspartate aminotransferase (AST) exist in the cytoplasm of hepatocytes, when the hepatocyte membrane is ruptured, ALT and AST will be obviously elevated, which is an important indicator reflecting the damage of hepatocytes. 3. Bilirubin metabolism: total bilirubin includes indirect bilirubin and direct bilirubin. Jaundice can occur if there is any obstacle in the conversion of indirect bilirubin to direct bilirubin. Measurement of serum bilirubin can help detect jaundice that is not yet visible to the naked eye and often reflects hepatocellular damage or cholestasis. The above liver function markers do not exactly parallel the health of the liver, so liver function should be evaluated in conjunction with the patient’s signs and symptoms, imaging and pathology. If you have any liver problems, you need to consult a doctor to determine the cause of the problem and, if necessary, treat it accordingly.