Left subcostal pressure is generally due to pressure stimulation of subcostal lesions in the tissues or organs causing pain, commonly seen in the left lower chest wall trauma, left lower thoracic intercostal neuritis, left costochondritis at the rib arch, left epigastric organ disease, and so on. 1. Left lower chest wall trauma: such as left lower chest wall rib fracture and soft tissue contusion, pressure can cause the fracture end to move and dislocate or stimulate the inflammatory metabolites in the soft tissue of the contusion to stimulate the nerve endings, resulting in obvious pressure pain. 2. Intercostal neuritis in the left lower chest: because of the damage to the intercostal nerves, the pain threshold of the intercostal nerves and muscle tissues is lowered, and pressure can significantly induce pain in the lower part. 3. Left costal arch costochondritis: inflammatory disease of costal cartilage, mostly caused by non-infectious factors, pressure can cause periosteal pulling and tension, stimulation of nerve endings causing pain. 4. Left upper abdominal organs: stomach and spleen and other organs are located in the left quadrilateral rib area, gastritis, gastric ulcer, splenomegaly, pancreatitis and other diseases can cause the left side of the lower chest involving pain, pressing the left subcostal bone will appear obvious pain. Pressing pain under the left rib cage with severe pain that cannot be relieved for a long period of time, it is recommended to go to the hospital for further diagnosis and treatment.