Three major causes of stomach cancer: 1. Environmental and dietary factors Environmental and dietary factors are the most important causes of stomach cancer. Foods such as chemical fertilizers, industrial waste gas, food additives, mold, pickling, etc. all contain carcinogenic substances. In addition, frequent consumption of stimulating foods can lead to functional disorders and increase the chances of stomach cancer. 2.Stomach disorders such as chronic atrophic gastritis and gastric ulcer are 4-6 times more likely to cause stomach cancer than normal people. 3.Spiritual factors and genetics have a higher incidence of stomach cancer in introverted people who like to sulk, while those who are optimistic and cheerful have a lower incidence. In addition, the occurrence of stomach cancer is also related to heredity.