Pain in the left back rib cage in women may be caused by several reasons: 1. Soft tissue lesions around the left back rib cage. If you sit or stand with your head down for a long time, or if you have some bad posture, and if you get cold, it can cause spasm of the muscles around the ribs here, or a sterile inflammation of the deep fascia. These soft tissue lesions may cause pain around the rib cage. 2. Due to lesions of internal organs of the thoracic cavity. For women, it is more common in this area due to angina pectoris, myocardial infarction, lung inflammation, or pleural adhesions and a series of other diseases that lead to bony pain here. 3. osteoporosis. It is more common in elderly women, and once it develops, it may cause bony pain in many parts of the body, and the rib cage is also a good site. In addition, if you do some slight coughing or sneezing, it may cause pathological fracture of the ribs, which may lead to pain.