There are many clinical causes of sternal pain when breathing, which may be caused by the following factors: 1. It may be caused by aseptic inflammation of the rib cartilage, which usually occurs after cold, flu or exertion, and the patient will experience sternal pain when breathing, and the sternal pain disappears after holding the breath. 2. The patient will have coughing and other symptoms in addition to breathing sternal pain symptoms. 3, cardiovascular lesions caused by the more common clinical angina, coronary heart disease, myocardial infarction, etc.. Patients with symptoms of sternal pain when breathing should go to the hospital for relevant examinations such as chest CT and electrocardiogram, etc. to clarify the cause and then take active treatment measures.