Smoking is not recommended after gastroscopy, but when you want to smoke very much, it is recommended to smoke 2 hours after gastroscopy if it is simply a gastroscopy, and it is recommended to smoke at least 24 hours after gastroscopy if invasive operations such as treatments, biopsies, and so on are carried out at the same time as gastroscopy. Therefore, how long you can smoke after gastroscopy varies from person to person and needs to be judged comprehensively according to some other operations performed for gastroscopy. Gastroscopy may irritate the local mucosa, foreign body sensation in the throat, edema and other phenomena, if there is no invasive operation, usually in about 2 hours will be relieved, after the relief can be appropriate smoking. If invasive operations such as treatment or biopsy are performed during gastroscopy, the damage is greater and the recovery time is longer, it is recommended to smoke after gastroscopy and after 24 hours without any abnormalities. Since cigarettes contain nicotine, tar and other harmful substances, smoking may cause nausea, vomiting and other uncomfortable symptoms, which will have an impact on the body’s recovery, so it is best to quit smoking if you can to help your body recover. It is recommended that patients who experience discomfort one week after the gastroscopy, such as discomfort in the throat and loss of appetite, should be seen promptly.