1.Incognito symptoms Stomach cancer in young people are mostly about hidden pain and discomfort in upper abdomen, indigestion and loss of appetite, which are often considered as peptic ulcer or gastritis. Some women with gastric cancer during pregnancy are easily mistaken as pregnancy reaction. 2. Prone to bleeding Gastric cancer in young people is highly malignant and grows rapidly, with insufficient blood supply around the cancer, which easily forms ulcers and leads to upper gastrointestinal bleeding and perforation, and anemia appears earlier, often before vomiting blood or black stool. 3. Short course, rapid progress, early metastasis and poor prognosis The younger the age, the shorter the course of the disease, with the shortest course being only half a year, and a considerable number of patients have metastasis and extensive metastasis at the time of diagnosis, and soon appear cachexia.