Gastric cancer is one of the most common malignant tumors in China, with a higher incidence rate in the northwest and southeast coastal areas, and a higher incidence age between 41-60 years old, with more men than women. Trapped elements related to the development of gastric cancer include dietary disorders; consumption of food and water containing carcinogenic substances such as amines nitrite and polycyclic aromatic hydrocarbon compounds, moldy sauerkraut, smoked and pickled foods, alcohol; lack of vitamins in food; lack of chemical elements such as zinc in living environment; chronic atrophic gastritis with intestinal epithelial hyperplasia of gastric mucosa, polyps over 2 cm in diameter, chronic recurrent large and deep gastric ulcers; mental trauma and family history of cancer. Gastric ulcer; mental trauma and family history of cancer. Common early manifestations of gastric cancer include: 1. Upper abdominal discomfort and fullness There is often a feeling of burning, noisy and fullness in the abdomen, which is especially obvious after meals, and the symptoms are getting worse as the disease develops. These symptoms should be distinguished from indigestion and chronic gastritis. Indigestion often has a history of careless eating, overeating, while chronic gastritis often has a history of recurrent episodes. 2.Loss of appetite Early gastric cancer often suddenly manifests as loss of appetite and aversion to greasy food. This should be distinguished from hepatitis. Hepatitis often has systemic symptoms such as elevated transaminases, fever and weakness, yellow urine with strong tea color and jaundice. 3, nausea, belching, acid reflux and vomiting nausea is most obvious when the gastritis lesion is located in the pylorus at the gastric outlet. If the gastric outlet is completely blocked, a sour or egg-smelling odor will be belched out or vomiting will occur, with vomit being mostly persistent food and gastric juice. 4.Hidden pain in upper abdomen The pain of early gastric cancer is indefinite, or it may appear as continuous hidden pain, unlike gastric ulcer or duodenal ulcer, which has the characteristics of pain after meal or pain before meal. If the patient originally suffered from gastric or duodenal ulcer disease, the regularity of pain may be suddenly changed, and the drugs that were effective in treating ulcer disease suddenly become ineffective or significantly less effective. 5.Vomiting blood and black stool If the cancer only destroys small blood vessels, it is often manifested as “occult blood” in stool, that is, although the appearance of stool is normal, blood cells can be found in it by laboratory test. If the cancer invades larger blood vessels in early stage, it will cause vomiting blood and black stools or tar-like stools. The occult blood and black stool of gastric cancer are persistent and persistent, while the bleeding caused by gastric and duodenal ulcer is intermittent and can be stopped by timely treatment. 6. Rapid wasting and severe anemia Because cancer is a consuming disease, and gastric cancer causes digestive malabsorption and gastrointestinal bleeding, which aggravates the wasting and anemia. Knowing and being alert to the above early manifestations of gastric cancer is the key to early detection of gastric cancer. It is worth noting that the above six conditions may not necessarily exist in one patient or at the same time, as long as one of them appears, especially in men over 40 years old, they should be taken seriously and go to hospital for necessary examination in time.