Precancerous lesions: Precancerous lesions are benign diseases with a tendency to become cancerous, such as: (1) chronic atrophic gastritis, with a cancer rate of up to 10%; (2) chronic gastric ulcer, with a cancer rate of less than 3%; (3) gastric polyps, with a diameter of >2 cm, multiple and wide base, with a high cancer rate; (4) partial gastrectomy, with a cancer rate of up to 0.3%-10% in the remnant stomach; (6) other precancerous lesions on gastroscopic biopsy -(5) other precancerous lesions, such as giant gastric mucosal hypertrophy, warty gastritis, etc.; (6) gastroscopic biopsy pathology types: ① heterogeneous hyperplasia, also known as atypical hyperplasia, caused by chronic inflammation, such as the development of severe atypical hyperplasia can be considered as precancerous lesions or even considered as early cancer; ② colonic intestinal hyperplasia is closely related to the occurrence of gastric cancer. 2, poor dietary habits: such as irregular diet, fast eating, high salt/hot food, pickled, smoked, dried seafood, overnight dishes with high content of carcinogenic substances nitrite, red meat with barbecue, frequent consumption of moldy food, less fresh vegetables, etc. 3.Long-term alcoholism and smoking: alcohol can change the mucous membrane cells and cause cancer. Smoking is also a strong risk factor for gastric cancer, and those who start smoking in adolescence are at the greatest risk. 4.Family history of gastric cancer or esophageal cancer: the incidence of gastric cancer among patients’ family members is 2~3 times higher than normal population. 5.Long-term poor psychological status: such as depression, sadness, pining, loneliness, depression, hatred, disgust, low self-esteem, self-blame, guilt, interpersonal tension, mental breakdown, sulking, etc., the risk of stomach cancer is significantly higher. 6.Some special occupations: long-term exposure to sulfuric acid dust and mist, lead, asbestos, herbicides and metal industry workers have significantly higher risk of stomach cancer. 7.Geology and water quality containing harmful substances: areas with volcanic rocks, high peat and deep and large faults have small Ca/SO4 ratio in water and high content of nickel, selenium and cobalt. Volcanic rocks contain high levels of 3,4 benzo(a)pyrene, and peat has high levels of organic nitrogen and other nitrosamine precursors, which can easily damage the gastric mucosa. Selenium and cobalt can also cause gastric damage, and nickel can promote the carcinogenic effects of 3,4 benzo(a)pyrene. 8, Helicobacter pylori (Hp) infection: some studies say that about half of gastric cancer is related to H. pylori infection. About 60% of the national population is infected with the bacteria, but only 0.03% of the population suffer from gastric cancer.