You can eat and drink water for routine blood tests. The routine blood test is a 24-hour test that can be done at any time throughout the day, to go to the hospital to check the routine blood test or the next day of hospitalization to draw blood for routine blood tests, up in the morning on an empty stomach to draw blood, often because a blood draw not only to check the routine blood, but also to check fasting blood sugar, lipids, liver function and other items that need to be checked on an empty stomach, so it is required that at least 12 hours do not eat anything containing calories, but, does not require fasting for 12 hours without drinking any water. There is no requirement to not drink any water during the 12 hours of fasting, you can drink some water appropriately. If a person has an acute illness or is in serious condition and needs to be rescued, an emergency blood test can be done at any time, regardless of the time of day, even if the patient has just eaten and drank water, the effect on the results of the blood test is not great.