The damage of smoking to the stomach includes damage to the gastric mucosa, leading to gastritis, gastric ulcer, and inducing gastric cancer. 1. Damage to gastric mucosa: nicotine in cigarettes can stimulate gastric mucosa, cause submucosal vasoconstriction and spasm so that gastric mucosa ischemia and hypoxia, and also promote the secretion of gastric acid, reduce gastric mucosal protective factors, leading to gastric mucosal damage. 2. Gastric diseases: gastritis, gastric ulcer, gastroesophageal reflux and many other diseases are directly related to smoking, and at the same time, due to the persistent damage caused by smoking, it will also reduce the cure rate of gastrointestinal diseases and increase the recurrence rate of diseases. 3. Stomach cancer: Nicotine and diethylamine in tobacco will produce carcinogenic substances such as nitrosamines in the body, which will induce stomach cancer, and also easily lead to lung cancer and intestinal cancer. Tobacco is a class I carcinogen specified by WHO, which is directly related to gastritis, gastric ulcer, gastric cancer, etc. It is recommended to quit smoking and develop healthy living habits. If you have stomach discomfort, you should go to the hospital in time.