Left chest pain may be associated with spontaneous pneumothorax, pleurisy, acute pericarditis, cardiovascular disease, pneumonia, costochondritis, etc. 1. Spontaneous pneumothorax: Spontaneous pneumothorax may be related to smoking, airway inflammation, emphysema, pulmonary pustules, etc. It can present with chest pain, chest tightness, dyspnea, shortness of breath, and other symptoms. 2. Pleurisy: generally due to bacterial or viral infection, autoimmune diseases, tumors, etc. Patients may also have pleural effusion at the same time, which can be manifested as symptoms of pain in the left chest cavity, and there may also be symptoms of dyspnea, coughing, sputum, fever and so on. 3. Acute pericarditis: it may be related to infection, neighboring organ disease, pericardial inflammation makes the pericardial cavity fibrous hyperplasia, restricting the normal activity of the heart, which may cause left chest pain, palpitation, dyspnea, fever and other symptoms. 4. Cardiovascular disease: angina attack in patients with coronary heart disease will cause pain in the precordial area, chest tightness, shortness of breath and discomfort, which is more likely to occur after activity and exertion, satiety, emotional excitement and cold. 5. Pneumonia: extensive pneumonia has the possibility of causing solid changes in the lungs, which can cause severe coughing, or secondary complications such as pleurisy, resulting in left chest pain. 6. costochondritis: costochondritis caused by trauma, immunity, strain, infection and other factors can also cause left chest pain. Left chest pain also need to exclude gastritis and other diseases, to go to the hospital in time to do the examination to exclude diseases, identify the causes under the guidance of the doctor treatment.