The process by which the mucosal state of the esophagus, stomach, duodenal bulb and even the descending part can be observed sequentially and clearly through gastroscopy, and the pathology and cytology of the biopsy can be performed, is called gastroscopy. Gastroscopy is diagnostically reliable and safe. What are the precautions for gastroscopy? 1, the first day no smoking, so as not to cough during the examination to affect the intubation; no smoking can also reduce the secretion of gastric acid, so as to facilitate the doctor’s observation. 2.Patients should fast for at least 6 hours before the examination. If the examination is conducted in the morning, fasting is required after dinner the day before and breakfast is not required on the same day; if the examination is conducted in the afternoon, light semi-liquid food can be eaten for breakfast and fasted at noon. Serious illness and physical weakness after fasting physical strength is difficult to support the examination should be intravenous hypertonic glucose solution before the examination. 3, in order to eliminate the patient’s nervousness, reduce gastric juice secretion and gastric peristalsis, drive away the foam in the stomach, so that the image is clearer, if necessary, the doctor 20-30 minutes before the examination to give the patient with sedatives, antispasmodics and expectorants. In this regard, the patient should be aware of this and give cooperation. 4, in order to make the gastroscope can pass through the pharynx smoothly, do gastroscopy before the general use of pharyngeal anesthetics, the use of drugs to the patient should be in accordance with the requirements of the doctor. 5, the patient and the doctor to cooperate, the patient before the examination to urinate to empty the bladder, into the examination room, loosen the collar and trouser belt, remove the dentures and glasses, take the left side lying position, or as needed to change to other positions. After entering the mirror, you should not bite the mirror with your teeth to prevent breaking the plastic tube of the mirror body. The body and head should not be turned to prevent damage to the mirror and injury to internal organs. If there is any discomfort, the patient should tolerate it for a period of time. If the patient cannot tolerate it, he/she can indicate to the surgeon (doctor or nurse) with hand signals so that necessary measures can be taken.