Stomach cancer is a very common cancer, how common is it? According to statistics, stomach cancer ranks fourth in the world in terms of incidence rate and second in mortality rate after lung cancer, while China ranks second in terms of incidence rate and mortality rate among all cancers. Cancer is caused by the interaction between intrinsic genetic factors and external environmental factors, which leads to the cancerous transformation of normal cells in the body, but the exact causes of cancer are not fully understood, which is why it is difficult to prevent cancer at the root. However, this does not mean that we can do nothing at all. Through research, some risk factors for the development of cancer have been basically clarified. The risk factors of gastric cancer include: poor dietary habits (irregular diet, eating too fast and too full, overeating, etc.), unclean diet, preference for smoked and fried foods, long-term high-salt diet and pickled and smoked foods (such as pickled fish and salted vegetables), frequent consumption of moldy foods, preference for red meat, low intake of fresh vegetables and fruits, nutritional imbalance or deficiency, smoking and alcohol abuse, family history of gastric cancer, chronic atrophic gastritis, chronic gastric ulcer, gastric polyp or stomach surgery, Helicobacter pylori infection, etc. The following are some important risk factors for the development of gastric cancer: 1. Age. The risk of gastric cancer increases with age, and most gastric cancers occur after middle age, but in recent years, the incidence of gastric cancer tends to be younger, which should be taken seriously. 2. Gender. Men are more likely to get stomach cancer than women, about twice as much as women, so men, especially those who are middle-aged or older, should pay more attention to it. 3. Dietary factors. Diet plays an important role in the occurrence of gastric cancer, such as bad eating habits (irregular diet, eating too fast and too full, overeating, etc.), unclean diet, preference for smoked and fried food, long-term high-salt diet and pickled and smoked food (such as pickled fish and salted vegetables), frequent consumption of spoiled and moldy food, low intake of fresh vegetables and fruits, imbalance or lack of nutrition, smoking and alcoholism, etc. 4, H. pylori infection. H. pylori infection is very common, more than half of the people in the world have this bacterial infection, and the infection rate in developing countries is higher than that in developed countries. 1994, the World Health Organization identified it as a class I carcinogenic factor. 5. Family history of gastric cancer, chronic atrophic gastritis, chronic gastric ulcer, gastric polyp or history of gastric surgery.