The key to the diagnosis and treatment of gastric cancer lies in “three early stages”, i.e. early detection, early diagnosis and early treatment. According to research, it is a slow process from the beginning of cancer in a certain part of stomach tissue to the appearance of certain clinical symptoms and signs, and it is a gradual process from quantitative to qualitative changes. This process is medically called “pre-cancer” (e.g. toxic atypical hyperplasia). And this period is also the stage with the best treatment effect. Therefore, if we can pay attention to the early manifestations of gastric cancer, it is beneficial to early detection and early treatment. Therefore, if we can pay attention to the early manifestations of gastric cancer, it is conducive to early detection and early treatment, so that we can prevent the disease before it happens. Therefore, the following groups of people should be alert: chronic gastric ulcer, age above 45, family history of gastric cancer or stimulated by adverse external factors, and those who have discomfort should go to hospital for consultation and treatment in time. 1.More than 80% of patients with early symptoms of gastric cancer have pain in upper abdomen. 2.About 1/3 of patients with early symptoms of gastric cancer have stuffy stomach, epigastric discomfort, loss of appetite, indigestion, accompanied by panic acid. 3.Early symptoms of gastric cancer 1/3 patients may have unexplained weight loss, emaciation and fatigue, although they have no obvious digestive symptoms. 4.Some patients with early symptoms of gastric cancer show symptoms such as pantothenia, heartburn, nausea, vomiting, belching or black stool.