In clinical practice, left abdominal discomfort, but not pain, is mainly seen in the following three main categories of diseases: 1. The most common are mainly seen in gastric diseases, usually chronic superficial gastritis, or even gastric tumors. It can usually manifest as stomach discomfort, left abdominal discomfort, but not necessarily painful symptoms, and usually requires further gastroscopy. For superficial gastritis, it is usually treated with acid control and protection of gastric mucosa. For gastric tumors, surgery is usually required. If it is a malignant tumor, it usually requires radical resection of gastric cancer. 2. It is mainly seen in colon disease, which can show symptoms of incomplete intestinal obstruction, and usually requires further colonoscopy to clarify the diagnosis and surgery if necessary. 3. Even myocardial enzymatic examination is required, and further interventional stenting is usually required for severe coronary artery stenosis.