Pain in the left upper abdomen, mostly consider the following four diseases: 1. Gastric funditis, in addition to pain in the left upper abdomen, there are often nausea, vomiting, acid reflux and belching, and the diagnosis of gastritis can be clarified by gastroscopy. 2. When gastric cancer is located in the bottom of the stomach, it is manifested as nausea, vomiting and acid reflux, and the patient has progressive weight loss, as well as anemia, drowsiness and anorexia, and only gastroscopy can find gastric occupying lesions, which can be clarified by pathological biopsy. Cardia, cardia cancer, choking sensation when eating, along with pain in the left upper abdomen, can be clarified by esophagoscopy.3. Colon tumors, commonly malignant tumors in the splenic flexure of the colon, can appear as pain in the left upper abdomen when invading the surrounding tissues.4. Spleen tumors, in addition to pain in the left upper abdomen, can often be palpated as an obvious mass in the left upper abdomen with progressive increase in volume, can be clarified by abdominal CT examination.