Gastric diseases include gastritis, gastric ulcer and gastric cancer. 1. Gastritis: mainly includes acute gastritis, which is mainly caused by stress, drugs, alcohol, trauma and physical factors, duodenogastric reflux; chronic gastritis, which is mainly caused by Helicobacter pylori infection, duodenogastric reflux, autoimmunity, advanced age and lack of gastric mucosal trophic factor; and special types of gastritis or gastric disease, such as corrosive gastritis, which is caused by strong acid and alkali corrosion. 2. Gastric ulcer: mainly caused by Helicobacter pylori infection, drugs and gastric emptying obstacle, mainly postprandial pain. 3. Gastric cancer: it is a malignant tumor of stomach and the most serious gastric disease, mainly caused by environment and diet, infection, precancerous lesions, mainly indigestion symptoms in early stage, and epigastric pain, aggravation after meal, poor appetite, anorexia, etc. in progressive stage. Therefore, there are more common types of gastric diseases, including gastric polyps, gastric stones, pyloric obstruction and so on, in addition to the above common diseases, patients with any discomfort should consult the doctor in time for a clear diagnosis and early treatment.