If there is a history of trauma to the chest and pain occurs when sleeping on the left side, and the pain increases when coughing or breathing deeply, it is mostly considered to be a rib fracture and can be fixed with a rib band on the chest. If there is no rib fracture in the chest X-ray, it is mostly due to soft tissue injury such as muscle injury, and can be treated with oral non-steroidal anti-inflammatory drugs such as ibuprofen extended-release capsules, meloxicam, etc. You can also spray Yunnan Baiyao aerosol at the same time to activate blood circulation and remove blood stasis, reduce swelling and pain. If there is no history of trauma to the chest and the pain is accompanied by coughing, it is most likely due to pleurisy, which can be treated with oral or intravenous fluids and antibacterial drugs. If the pain is accompanied by night sweats and fever in the afternoon, it is usually considered to be tuberculous pleurisy and requires anti-tuberculosis treatment. If the site of pain is the left breast, it is mostly considered to be caused by cystic hyperplasia of the breast, which can be treated with oral administration of Zuoyao Pill, Xiaojin Pill or Mastication.