Biochemistry that is, biochemical examination, do biochemical examination drinking water will dilute the blood, affecting the accuracy of some test results. Biochemical examination is through the blood, urine and semen test to reflect the body’s liver function, kidney function, blood sugar, blood lipids, blood uric acid. Usually, fasting is required for blood biochemistry test, and if the patient is checking albumin, blood glucose, blood lipids, serum ions, etc., drinking water will dilute the blood, which will affect the final results of the above indexes, and cannot accurately reflect the patient’s condition. Therefore, it is recommended that patients undergoing blood biochemistry test should fast and abstain from food and drink for 6 to 8 hours, do not stay up late the night before the test, do not drink alcohol, and ensure a good state of the organism so that it can better reflect the physical condition. Before the biochemical test, patients can consult the relevant doctors in advance and follow the doctor’s advice to do the pre-test preparation.