Matters to note when doing gastroscopy: 1, fasting for 6-8 hours before the examination, in fasting, if there is food inside the stomach, it will affect the quality of the examination. 2, before doing gastroscopy to do electrocardiogram, do routine blood, hepatitis B two to half, HIV, syphilis and other tests to prevent cross infection. 3, patients with movable dentures, denture to take it out, because do painless gastroscopy 4, because of the afternoon examination, fasting time is longer, pay attention to rehydration, especially the elderly or patients with diabetes, to prevent hypoglycemia situation.