If the patient has stabbing pain above the left chest: 1, it is necessary to consider the external factors, such as trauma caused by the fracture of the left sternum or ribs, contusion, sprain, contusion, strain and other factors of the surrounding soft tissues, there will be a stabbing pain above the left chest. 2, for circulatory diseases, such as coronary heart disease, unstable angina pectoris, myocarditis, pericarditis, hypertrophic obstructive cardiomyopathy, infective endocarditis, there will also be the above symptoms. 3, for respiratory diseases, such as massive pneumothorax, thoracic infection, pleurisy, massive pneumonia, there will also be stabbing pain above the left chest. For respiratory diseases, such as massive pneumothorax, chest infection, pleurisy, massive pneumonia, there will be tingling pain above the left chest, and the tingling pain will be gradually aggravated with respiration.4 For female patients, such as lobular hyperplasia of the left breast, mastitis, tumors, or space occupation, there will be the above clinical symptoms.