Gastroscopy can be done in the afternoon, but to prevent the occurrence of hypoglycemia, it is generally recommended to do in the morning. Gastroscopy must be fasted for 6 to 8 hours before the examination, in the fasting state, to facilitate the emptying of gastric contents, is conducive to a clearer observation of gastric mucosal lesions, so as to avoid gastric contents to affect the microscopic observation. Most hospitals are conducted in the morning, because at this time the examinee after a night of digestion and emptying, gastric emptying state is in the best, gastroscopy is more accurate, the examinee’s body can also tolerate. However, it is not limited to the morning, and gastroscopy can also be done in the afternoon. Due to the longer period of fasting and dehydration, it is necessary to prevent hypoglycemia and other conditions. If gastroscopy is done in the afternoon, glucose water can be added during the long fasting period to prevent hypoglycemia without affecting gastric emptying. If there are special circumstances or conditions permit, gastroscopy can also be done in the afternoon, but it is necessary to prevent the occurrence of hypoglycemia. Consultation with the attending physician is recommended for specific examination appropriateness.