What are the main symptoms of gastric cancer? About 70% of early gastric cancer can be asymptomatic. According to the mechanism of occurrence, the symptoms of advanced gastric cancer can be divided into 4 aspects: 1. Energy consumption and metabolic disorders due to cancer proliferation, resulting in low resistance, malnutrition, vitamin deficiency, etc., which are manifested as weakness, lack of appetite, nausea, emaciation, anemia, edema, fever, constipation, dry skin and hair loss, etc. 2. Upper abdominal pain, gastrointestinal bleeding, perforation, etc. caused by ulceration of gastric cancer. The pain of gastric cancer is often biting in nature and has no clear relationship with eating or worsens after eating. Some pains like peptic ulcer can be relieved by eating or antacids, which can be maintained for a long time, and then the pain gradually worsens and persists. When the cancer bleeds, it is manifested as positive fecal occult blood test, vomiting blood or black feces. 5% of the patients show heavy bleeding, and there are even those who seek medical attention for the first time due to bleeding or acute abdomen such as gastric cancer perforation.3. Symptoms caused by mechanical effects of gastric cancer, such as feeling of fullness and heaviness due to poor gastric filling, as well as tastelessness, anorexia, pain, nausea, vomiting, etc. Gastric cancer located near the cardia can invade the esophagus, causing hiccups and difficulty in swallowing, and located near the pylorus can cause pyloric obstruction. 4.Symptoms caused by cancer spreading and metastasis, such as ascites, hepatomegaly, jaundice and metastasis of lung, brain, heart, prostate, ovary, bone marrow, etc., which cause corresponding symptoms. Which patients should be alert to the occurrence of gastric cancer The treatment effect of gastric cancer depends on early diagnosis and treatment. Those who have the following conditions should be highly alerted and timely undergo barium meal X-ray, gastroscopy and biopsy to make a clear diagnosis: ① those who start to have discomfort or pain in the middle and upper abdomen after the age of 40 without obvious rhythm and accompanied by obvious lack of appetite and wasting; ② those who have gastric ulcer and whose symptoms do not improve even after strict medical treatment; ③ those who have chronic atrophic gastritis with intestinal epithelial hyperplasia and severe atypical hyperplasia (iii) patients with chronic atrophic gastritis with intestinal epithelial hyperplasia and severe atypical hyperplasia who have failed medical treatment; (iv) patients with gastric polyps larger than 2 cm on X-ray; (v) patients of middle age or older with unexplained bleeding, anemia, wasting and persistent positive fecal occult blood.