Gastric diseases are a large group of diseases, including acute and chronic gastritis, gastric ulcer, gastric polyp, gastric stone, etc. Not all of them will produce cancer. In general, if patients have early diagnosis, early detection and early treatment, the disease will be better controlled and no cancer will occur. However, it does not mean that there is no possibility at all. If patients have the following symptoms, it may be the precursor of cancerous gastric disease: 1. Upper abdominal pain: Since many stomach diseases can lead to the symptoms of upper abdominal pain, they cannot be taken seriously by patients. When the abdominal pain becomes continuous, irregular and severe, and the pain increases when eating, and the feeling of fullness can be produced after eating less, the patient should be alerted; 2, wasting: such as gastritis or gastric ulcer can lead to nausea, vomiting, diarrhea, exertion, weakness and other symptoms, and when these symptoms persist for a long time and cannot be relieved, or even increase, causing the patient to suddenly lose weight in a short period of time, the patient should be alerted to such gastric diseases If the patient has not consumed abnormal food, the diet is the same as usual, but there is unexplained black stool, it is necessary to be vigilant, and the patient is advised to go to the hospital for fecal occult blood test, if the result is consistently positive, and serious anemia occurs, it may indicate that the gastric disease is malignant; 4, upper abdominal morphological changes: if the upper abdomen appears bulging, swelling or can touch the mass when pressing If there is a bulge or swelling in the upper abdomen or a mass that can be touched when pressed, and the mass is painful when pressed and radiates in all directions with the stomach as the center, there is a greater possibility that there is a tumor and the patient may have gastric cancer. In addition, anemia, loss of appetite or other abnormal symptoms that appear suddenly may also be the precursor of deterioration or cancer of stomach disease. Patients are advised to actively cooperate with doctors for treatment and have regular follow-up examinations so that timely and accurate control can be performed at the time of early deterioration.