Left chest pain during inhalation is often considered pleurisy, pneumothorax, coronary heart disease, etc., can be treated with medication, surgery, etc., medication should follow the doctor’s instructions. 1. Pleurisy: such as tuberculosis pleurisy caused by tuberculosis bacillus, chest pain is mostly sharp stabbing pain, aggravated by deep breathing, and dyspnea is especially obvious when the amount of pleural effusion is large. Drug treatment refers to anti-tuberculosis drug treatment, such as streptomycin, rifampicin, etc.. 2. Pneumothorax: gas enters into the pleural cavity due to trauma and forms pneumothorax, which is mostly acute in onset, with chest pain and dyspnea as the main manifestations. Treatment includes thoracocentesis, closed chest drainage, and thoracoscopic surgery or open thoracic surgery if the internal medicine treatment is not effective. 3. Coronary heart disease: Coronary artery lumen narrowing or obstruction, resulting in myocardial ischemia, hypoxia or necrosis, patients often experience dyspnea, chest pain and other symptoms. Nitroglycerin and aspirin can be taken, and those who cannot be relieved by medication are treated with surgery, including percutaneous coronary intervention and coronary artery bypass grafting. There are other causes of left chest pain during inspiration, and it is recommended that patients seek medical attention in time to avoid delaying their condition.