Generally speaking, 6-8 hours of fasting and 4 hours of water fasting are required before painless gastroscopy. Fasting is required before gastroscopy because gastroscopy, especially under general anesthesia, can easily lead to nausea and vomiting, and if there is food and water in the stomach, it can easily lead to accidental inhalation of food or water into the esophagus and lungs during vomiting, resulting in choking, suffocation and aspiration pneumonia. Moreover, if there is food inside the stomach, it may obscure the view of the gastroscope, which is not conducive to the diagnosis and treatment of the disease. It should also be noted that the diet before the gastroscopy should be light, well-digested fluids or semi-fluids, such as rice porridge, soft noodles, etc.; usually take aspirin and other antiplatelet drugs, should be discontinued a week ahead of time; patients with high blood pressure usually have poor blood pressure control, to normalize the use of antihypertensive drugs. Painless gastroscopy should be carried out in accordance with the doctor’s instructions, good preparation, to ensure the smooth progress.