Liver function usually refers to liver function, liver function test drank water, it is recommended that patients fasting the next day to check again. Before doing the liver function test, patients need to draw blood on an empty stomach, usually for 8 to 12 hours to ensure the accuracy of the test. After drinking water, the concentration of the components in the blood will be affected, and it will be due to the sudden increase in blood volume, resulting in the thinning of the blood, which will lead to a decrease in certain indicators in the blood routine or a decrease in the specific gravity of urine in the urine, which will in turn lead to an error in the results, affecting the judgment of the physical condition. It is recommended that after ten o’clock in the evening of the day before the blood test, you need to fast and abstain from food and water, and then get up early and go to the hospital for the blood test, which will be conducive to the accuracy of the results and prevent errors.