The hazards of gastric cancer are as follows: 1. Early stage manifests as gastrointestinal discomfort, including nausea, vomiting, upper abdominal discomfort, loss of appetite and other symptoms; 2. Late stage manifests as emaciation, poor spirit, and in serious cases, combined with gastric perforation and gastric bleeding, which is life-threatening. Gastric cancer is a malignant tumor and has a high degree of malignancy. The later the stage of the disease, the worse the prognosis. If gastric cancer is detected at an early stage, early diagnosis and early surgery, the harm will be relatively reduced. In the middle and late stages, especially in the late stage, even if patients undergo surgery, their survival rate and quality of life will be seriously affected.