There are many preparations and precautions before gastroscopy, generally including perfecting the preoperative examination, dietary restrictions, adjusting medication and so on. Gastroscopy belongs to a kind of routine means of examination, and patients generally need to perfect blood routine, blood biochemistry, coagulation function, blood-borne pathogen-related tests, electrocardiogram, chest CT and so on according to the doctor’s requirements before gastroscopy, in order to exclude potential risks. Next is the need for fasting, it is generally recommended to fast for 6 hours before the gastroscopy, and usually need to take local anesthetic before the examination, also need to empty the bladder of urine. Then you should stop taking anticoagulant drugs as much as possible before the operation, if you have to take drugs, please talk to your doctor in advance, and listen to your doctor’s advice on whether you need to stop taking other drugs. Although gastroscopy is a routine examination, there are relative contraindications. Gastroscopy is not recommended for patients with cardiopulmonary insufficiency who cannot tolerate the examination. If in doubt, please consult a medical professional.