With the navel as the center, a line is drawn horizontally and a line is drawn vertically to make a cross shape, and the left upper quadrant of the area is the left epigastrium. There are relatively few organs in the left upper abdomen, including part of the stomach, the spleen, the splenic flexure of the transverse colon, and the caudal part of the body of the pancreas and the left adrenal gland. If pain and lesions occur in the left upper abdomen, it is more likely to consider lesions of the stomach. It is common to have gastritis or gastric ulcer, as well as the possibility of gastric cancer. Stomach symptoms are atypical, mostly symptoms of the digestive tract, such as nausea, vomiting, abdominal pain, acid reflux, belching, etc. Sometimes black stools can be manifested when there is bleeding in the stomach. Gastroscopy is routinely needed to detect the lesions in the stomach, whether they are inflammation, ulcers or malignant tumors, and the next step of treatment can be decided after the diagnosis is clear.