(1) Upper abdominal discomfort and fullness: there is often a burning, noisy and full feeling in the abdomen, especially after meals, and the symptoms become increasingly worse as the disease progresses. These symptoms should be distinguished from indigestion and chronic gastritis. Indigestion often has a history of indiscretion and 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 pronounced 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 is belched out or vomiting occurs, with the vomit being mostly persistent food and gastric juice. (4) Occult pain in the upper abdomen: The pain of early gastric cancer is indefinite, or it may appear as continuous occult 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 stool or tar-like stool. 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 with 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 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 women over 40 years old, they should be taken seriously and go to hospital for necessary examination in time.