Drinking water before measuring blood glucose, whether the result is high or low depends on the amount of water consumed as well as the type of water. If it is mineral water or plain water, drinking a small amount of water usually does not have much effect. If it is a sugary drink, the blood glucose may increase after drinking it. If you drink unsweetened mineral water, purified water or plain water on an empty stomach after waking up in the morning, a small amount of water will generally have little effect on the results of blood glucose monitoring, and your blood glucose will not increase or decrease as a result. Drinking cola, milk tea, coffee, etc. may affect the blood glucose test results because these drinks contain a lot of sugar, and the blood glucose level will continue to increase after drinking them, and the blood glucose level of the test will also rise. If you are testing fasting blood glucose, try not to eat or drink, blood glucose two hours after a meal can be appropriate drinking water, specific should be operated under the guidance of the doctor.