There are many reasons for vague pain in the left rib cage, including overwork, disease (such as intercostal neuritis), trauma and so on. 1. Overwork: common heavy laborers, due to long hours of work, such as carrying cement, lifting and installing light fixtures and other work, resulting in the intercostal muscles in a prolonged period of time in the state of stretching, which leads to vague pain in the ribs. It is also common in weightlifters. 2. Diseases: such as myofasciitis, costochondritis, intercostal neuritis, myofasciitis around the ribs, pancreatitis, gastritis, gastric hemorrhage, etc., may reflexively cause pain in the left rib. 3. Trauma: If the left side of the ribs are impacted or squeezed, resulting in rib fracture, bone fracture or contusion of the sternum or soft tissues around the ribs, there will be hidden pain in the rib area. In addition to the above reasons, heart disease cannot be ruled out. If the above symptoms occur, it is recommended to go to the hospital in time for early and regular treatment.