Liver function tests are usually performed by drawing venous blood on an empty stomach, which means fasting for more than 8 hours to allow the stomach to empty and exclude food-induced disturbances. The liver function test is part of the laboratory test, which mainly examines bilirubin metabolism, enzyme metabolism and coagulation function, including bilirubin, transaminases, albumin, globulin and coagulation function related indexes, etc. Therefore, the liver function test is performed by drawing venous blood on an empty stomach, and the liver function evaluation is based on all indexes.