Left chest and back pain may be caused by tumor, heart disease, intercostal neuralgia, pneumonia and pleural effusion, which can be treated by surgery, radiotherapy and medication. 1. Tumor: Lung tumor will lead to lung function lesions, resulting in respiratory system damage, which may lead to vague pain in the left chest and back. If the tumor is diagnosed, the patient can have the tumor surgically removed. If the tumor is malignant, chemotherapy or radiotherapy should be carried out under the guidance of doctor to inhibit further development of the tumor. 2. Heart disease: Hidden pain in the left chest and back may also originate from angina pectoris caused by coronary atherosclerotic heart disease. At this time, you can follow the doctor’s instructions according to the type of angina to take drugs, such as aspirin, clopidogrel and other drugs, and in serious cases, through interventional stents, bypass grafting and other ways of treatment. 3. Intercostal neuralgia: Intercostal neuralgia can also lead to back and left chest pain. At this time, you can follow the doctor’s instructions through drug treatment, such as methylcobalamin and oxcarbazepine and other drugs, and in severe cases, surgical treatment to reduce the compression of intercostal nerves, such as radiofrequency temperature-controlled thermal coagulation and so on. 4. Pneumonia and pleural effusion: Inflammation of the lungs will stimulate the pleura, which will lead to chest and back pain, at this time, you can follow the doctor’s instructions according to the type of pneumonia using azithromycin and penicillin and other drugs. Pleural effusion can lead to excessive pressure in the chest cavity, creating an outward thrust that causes pain in the left side of the chest and back, which should be treated with thoracocentesis and drainage. If the patient’s pain is not relieved, he should go to the hospital in time, do not delay the treatment, and the medication should be strictly in accordance with the doctor’s instructions. Drugs should be used under the guidance of a doctor, avoid self-medication.