First of all, the lower left breast may be a problem of the breast or ribs and soft tissues around the ribs. If the left breast is painful, the most common is ligament strain or mastitis, you can choose to wear suitable loose and lifting role of the external fixation of underwear. If the pain is caused by a strained ligament, you can use local topical and oral blood-strengthening drugs, if the pain is caused by mastitis, you can use topical Jinhuang San, and go to a regular hospital to check the blood count and observe whether the white blood cells are elevated, if they are elevated and higher than normal, you should take oral antibiotics (such as cephalosporins) and Chinese medicine. If the pain is in the ribs and surrounding soft tissues, it is likely to be a rib fracture, pleurisy and other chest diseases, and should be clearly diagnosed and treated symptomatically.