Stomach cancer is usually found in middle-aged and elderly people, and the peak age of incidence is 50 to 80 years old, but in recent years, the trend of stomach cancer is gradually becoming younger, and the youngest stomach cancer patient treated before is only 16 years old. Experts believe that the trend of lowering the age of stomach cancer has a lot to do with poor work and rest, unreasonable diet structure, eating too fast and too hot, drinking and smoking for a long time, and indifferent response to gastrointestinal discomfort. Also a country with high incidence of stomach cancer, the early detection rate of stomach cancer in China is far worse than Japan and Korea. The Japanese government has funded the screening of gastric cancer among people over 40 years old since 1963, and the early detection rate of gastric cancer in Japan is more than 60%; Korea has conducted screening among people over 40 years old, and the early detection rate of gastric cancer is also about 40%; while more than 90% of the hospitalized cases of gastric cancer in China are progressed to the middle and late stage before seeking medical treatment. Many people, because they do not have in-depth understanding of their diseases or have the mentality of fluke, often just treat the symptoms without further examining the causes, thinking that only severe pain indicates that the stomach disease has become cancerous. In fact, some symptoms of upper abdominal discomfort, such as mild stomach pain, swelling and heaviness, vague pain in the heart fossa, etc. are early signs of stomach cancer. In addition, if the cancer occurs in the gastric sinus, changes in duodenal function may occur and rhythmic pain may appear. And this symptom is extremely similar to gastric ulcer. If you subjectively think that it is just a gastric ulcer and take medicine by yourself, it is easy to delay the correct treatment. The early symptoms of gastric cancer are easily confused with other diseases and often misjudged as gastric ulcer, simple polyps in stomach, benign tumor, sarcoma, chronic inflammation in stomach. Therefore, patients with unsatisfactory results after regular treatment and gradually losing weight should consider the possibility of gastric cancer, and if they can review gastroscopy and biopsy the lesions within a short period of time, it can reduce misdiagnosis and achieve the purpose of early intervention and timely prevention and treatment. Therefore, experts especially remind that people without gastric disease should be more alert to the possibility of gastric cancer once black stool appears. Especially when it is not easy to stop even after general diet control or taking gastric medicine, one should go to hospital for examination in time. In addition, unexplained weakness, emaciation or anemia are also obvious manifestations of the progress of gastric cancer. If the pain pattern of the original chronic gastric disease changes or recurring after treatment, it is also necessary to raise alert.