Left chest pain may be pneumothorax, pneumonia, pleurisy, angina pectoris, intercostal neuritis, reflux esophagitis and other diseases, you can take antibiotic drugs such as ceftazidime, morphine and other painkillers, rifampicin and other anti-tuberculosis drugs for the cause. 1. Pneumothorax: When the left chest wall is damaged or the lung surface is damaged, the outside gas enters into the pleural cavity through the broken place and causes severe chest pain. You can take morphine, diazepam and other analgesic and sedative drugs to relieve pain, but only for stabilizing a small amount of pneumothorax. 2. Pneumonia: Bacterial infection of the left lung tissue causes local inflammatory reaction and leads to pain. It can be treated with antibiotics such as amoxicillin, azithromycin, ceftazidime and moxifloxacin. 3. Pleurisy: Bacterial infectious pleurisy can be treated with antibacterial drugs such as levofloxacin, azithromycin, ceftriaxone, etc. Tuberculous pleurisy can be treated with anti-tuberculous drugs such as rifampicin, isoniazid, ethambutol and pyrazinamide. 4. Angina pectoris: coronary artery stenosis leads to myocardial ischemia and left chest pain, which can be treated with drugs such as nitroglycerin, aspirin and resuvastatin. 5. Intercostal neuritis: Reflex pain along the intercostal space caused by infection of the left intercostal nerve. You can take vitamin B, ibuprofen and other drugs to treat it. 6. Reflux esophagitis: stomach acid reflux into the esophagus corrosion of the esophageal wall resulting in left chest pain, you can take eplazole, cimetidine, domperidone, aluminum magnesium carbonate and other drugs. Pay attention to the use of drugs under the guidance of a physician.