The left side of the chest pain may be related to rib fracture, costochondritis, angina and other diseases, should be timely consultation to identify the cause of the disease. 1. Rib fracture can also lead to the symptom of pain in the left side of the chest, which is due to violence, trauma caused by rib continuity disruption, the fracture can stimulate the intercostal nerves and lead to chest pain, deep breathing, coughing or exercise pain can be exacerbated, while breathlessness and static is reduced. 2. The left chest pain may be caused by the left chest chondromalacia, chondromalacia is an inflammatory lesion that occurs in the rib cartilage area (the junction of the ribs and the sternum), which is divided into non-infectious chondromalacia and infectious chondromalacia. (1) The cause of non-infectious costochondritis is not clear, and it may be related to trauma, chronic strain, etc. There may be symptoms such as swelling and elevation of the costochondral area, localized pain, and obvious pressure pain when pressed. (2) Infectious costochondritis is mostly due to postoperative infection of pathogenic bacteria, often manifested as local costochondral area of the skin redness, swelling, heat, pain and elevated body temperature, local soft tissue necrosis, abscess can be formed, and sinus tracts can be formed after rupture. 3. Patients with angina pectoris may experience pain in the left side of the chest as soon as they exert themselves due to labor, often accompanied by palpitations, dyspnea and other symptoms, and the pain in the left side of the chest can be relieved after rest. In addition to the above factors, may also be caused by other diseases, it is recommended to seek medical treatment as soon as possible, to the regular hospital to identify the causes, so as not to delay the condition.