The left side of the lower sternum pain should first clarify the cause of the disease, and then targeted treatment, this symptom is most common in rib fracture, intercostal neuralgia, heart disease, often take drugs, physical therapy, surgery and other ways. 1. Rib fracture: If the fracture is caused by external impact, the pain under the sternum may appear, and it is necessary to carry out chest radiograph or CT examination to make it clear, and if necessary, carry out surgical treatment, and infrared irradiation and other physical therapy, and take painkilling medicines to treat it, such as diclofenac sodium, ibuprofen and so on. 2. Intercostal neuralgia: this kind of patients can apply nerve-nourishing drugs under the guidance of doctors, such as methylcobalamin, B vitamins, and take ibuprofen extended-release capsules if the pain is more obvious. 3. Heart disease: when there is myocardial ischemia, infarction, angina pectoris, there can be radiating pain, which is manifested as pain under the left side of the sternum, and in severe cases, there can be a sense of pressure, a sense of dying, shock, etc., you need to go to the hospital to improve the examination, the need for medication or interventional therapy, the drug can be selected from aspirin, nitroglycerin and so on. The left side of the lower sternum pain may also have other causes, such as stomach diseases, etc. Do not blindly take drugs on your own, it is recommended to go to the hospital for further examination and choose the appropriate treatment.