Liver function test can drink a small amount of plain water, the amount should not be too much, but do not drink tea, beverages and so on. Liver function test can reflect the functions of liver metabolism, secretion, excretion and biotransformation, as well as the degree of liver cell damage, the test items include serum total protein, total bilirubin, direct bilirubin, ALT, AST, ALP, GGT, white/globule ratio and so on. Fasting is required for the liver function test because when fasting, the digestion and absorption of food is basically completed and the blood composition is basically stabilized, thus reducing the impact on the test results. Fasting needs to be fasted for more than 8 hours, and it is generally recommended to start fasting at 8:00 p.m. the day before the blood is drawn, and draw the blood at 8:00 a.m. to 10:00 a.m. the next day. During the fasting period, you can drink a small amount of plain water, try not to exceed 100 ml. In case of abnormal liver function test results, it is recommended to consult a doctor in time to clarify the cause of the disease with the help of the doctor and carry out targeted treatment or therapy.