Left upper abdominal pain may be caused by stomach diseases, but it may also be caused by the presence of other factors, such as left upper abdominal soft tissue injury, left lung or heart disease, etc. The pain may reflect or lead to left upper abdominal pulling pain, so it is recommended to seek medical attention in time to improve the examination and make a clear diagnosis. 1, stomach diseases: mostly gastritis, gastric ulcer and other diseases are common, especially if the lesion is located on the side of the large curvature of the stomach, that is, near the left upper abdomen, it can cause left upper abdominal pain, and patients can be accompanied by acid reflux, erratic and other symptoms; 2, left upper abdominal soft tissue injury: if the left limb is under pressure or excessive weight bearing, it can lead to muscle lactic acid accumulation, or even strain and tear, which can also trigger left upper abdominal pain, and such people usually have a history of local stress. If the left upper abdominal costochondritis occurs, the symptoms of left upper abdominal pain will also appear, and the pain site can change with the change of position; 3, left lung lesions: if the body due to pneumonia, tuberculosis, lung malignant tumors and other lesions produce inflammatory exudate material or pleural metastases, and lead to adhesion of the left pleura, will also be in breathing due to the thorax, lung tissue movement for pleural pulling effect, and then 4, cardiac lesions: patients with left upper abdominal pain cannot exclude the possibility of myocardial infarction, once this happens, due to acute ischemic necrosis of the myocardium, the exudate produced by the necrotic tissue stimulates the peripheral nerves and may cause left upper abdominal pain; 5, other: internal organs of the left upper abdomen, such as the pancreas, peritoneum and other lesions, can lead to pain around the lesion, causing left upper abdominal pain. Therefore, when patients have left upper abdominal pain, they need to selectively complete relevant examinations with specific medical history and symptoms, so as to clarify the specific condition, and not to blindly make judgments and treatment. Effective therapeutic measures can then be taken to cure the pain.