Stomach cancer is one of the most common malignant tumors in China, with nearly 400,000 new cases each year. With the development of the disease, symptoms similar to gastritis or gastric ulcer may gradually appear, including upper abdominal fullness and discomfort or hidden pain, acid reflux, belching, nausea, vomiting, loss of appetite, indigestion, black stool, etc. Especially when accompanied with symptoms such as weight loss, anemia and low blood sugar, gastroscopy and other examinations should be done in hospital in time. Prevention of gastric cancer: (1) Change bad eating habits. Do not eat or eat less fried, smoked, fire-baked, pickled or moldy food, because such food can contain some carcinogenic substances; overeating, which is a damaging stimulus to the stomach, also has a certain relationship with the occurrence of stomach cancer. (2) Improve nutrition. Increase the intake of animal protein, soybean products and fresh vegetables, fruits, etc. in appropriate amount. Rich vitamins can protect gastric mucous membrane cells, and balanced nutrition can improve the immune function of human body. (3) Do not smoke and drink less alcohol. Smoke contains many carcinogenic or carcinogenic substances, while strong alcohol can damage the gastric mucosal tissue and promote the absorption of carcinogenic substances. (4) Treat H. pylori infection. H. pylori infection has a great relationship with the occurrence of gastric cancer. Patients found to be infected with H. pylori should be treated actively. (5) Actively treat precancerous lesions. Atrophic gastritis, gastric ulcer and gastric polyp have the tendency to become malignant, and pernicious anemia has a certain relationship with gastric cancer. Treatment of gastric cancer: At present, the comprehensive treatment mainly based on surgery is advocated. Surgery is the main means of treating gastric cancer and the only way to cure gastric cancer. The advantage of chemotherapy is that it is a systemic treatment, which can kill the primary, residual, spreading or metastatic cancer cells. The disadvantage of chemotherapy is that it has a lot of toxic side effects and causes some kind of damage to the whole body. Other treatment methods include radiotherapy, biologically targeted therapy, immunotherapy and Chinese herbal medicine.