Drinking a glass of water in the morning is usually not considered fasting. Fasting in the clinical sense generally means ensuring that no food, water, etc. is eaten or consumed after twelve o’clock the night before, i.e., that no substances are ingested for about eight to ten hours. This is to ensure that you are in a state of fasting. Before performing certain tests, a fasting state is often required to ensure accurate results, such as blood glucose, blood lipids, liver function, kidney function, abdominal ultrasound and so on. In the case of fasting, the stomach and intestinal contents are basically discharged from the body, which can make the mucosa of the gastrointestinal tract show more clearly and accurately determine the location of the lesion. So if you have the above checkups, it is usually not recommended to drink water. If you get up in the morning and drink water, but need to carry out clinical examination or treatment, you should promptly tell the doctor about the situation.