Left-sided anterior chest pain, if there is a clear history of trauma, the possible causes are soft tissue injury of the chest wall, rib fracture or sternal fracture. If there is no clear history of trauma and left-sided anterior chest pain occurs, the possible causes are as follows: a. If the pain occurs after emotional excitement or strenuous activity and can be relieved after rest, it is generally considered to be cardiogenic pain, such as angina pectoris or heart attack. Second, if the pain occurs after a cold, or combined with fever, cough, sputum, chest tightness and other respiratory symptoms, generally consider that it may be caused by pneumonia or pleural inflammation. Third, a few left-sided anterior chest pains may be caused by chondromalacia or intercostal neuralgia.