There are many reasons why the sternum sometimes hurts and sometimes doesn’t, such as coronary artery spasm, intercostal neuralgia, digestive system diseases and so on. 1. Coronary artery spasm: myocardial ischemia will cause coronary artery spasm, which may cause the phenomenon of sometimes pain sometimes no pain in the sternum, especially in overeating, emotional excitement, which will trigger the pain attack. 2. Intercostal neuralgia: stimulation or compression due to thoracic spine lesions, viral attack, chemical injury, etc., triggering inflammatory reaction, mainly paroxysmal, mostly in the chest in a band-like distribution, coughing can be exacerbated, so it will be manifested as the sternum sometimes hurts and sometimes doesn’t. 3. Digestive system diseases: chronic gastritis, gastric ulcer and other diseases, after overwork or catching a cold, there can be an acute attack, so it will cause the phenomenon of sternal pain sometimes and sometimes not pain, accompanied by nausea, belching and other phenomena. Sternum sometimes pain sometimes not pain for many reasons, after the emergence of symptoms, it is recommended to go to the hospital in a timely manner to improve the examination, after a clear diagnosis, follow the doctor’s instructions to take standardized treatment.