Can I drink water before a liver function test?
Aug 01, 2025
Source: Cainiu Health
Dr. Gao Jun
Introduction
Under normal circumstances, you should not drink water before a liver function test. It is recommended to remain fasting for 8–12 hours before undergoing a liver function examination, during which time you should avoid both drinking water and eating. If there are special circumstances, such as diabetes or other conditions requiring regular medication, you may consult your doctor to determine whether you can take your medication with a small amount of water.
Generally, you should not drink water before a liver function test. Detailed explanations are as follows:
In liver function tests, multiple indicators can be affected by the concentration or dilution status of the blood, such as albumin and total bilirubin. Drinking large amounts of water before the test increases the blood's water content, which may dilute these indicators' concentrations, leading to lower measured values and affecting the physician's accurate assessment of liver function. The impact of water consumption is even more pronounced when testing items such as blood lipids.
Before undergoing a liver function test, it is recommended to remain fasting for 8–12 hours, during which time you should avoid both eating and drinking water. If there are special circumstances—for example, if you have diabetes and need to take medication regularly—you can consult your doctor to determine whether you can take your medication with a small amount of water. After completing the test, you can resume normal water intake and eating to replenish the body's needed fluids and energy.
