Pain in the middle of the chest is closely related to local tissue abnormalities, which may be caused by physiological factors, such as strenuous exercise or compression, or pathological factors, such as osteoarthritis, reflux esophagitis, myocardial ischemia, and so on. 1. Physiological factors. (1) Strenuous exercise: after strenuous exercise, it will cause an increase in the activity of the surrounding bone and joint and an increase in anaerobic fermentation, leading to the accumulation of lactic acid and causing localized soreness. (2) compression: sleeping process prone, resulting in localized compression, can also cause pain and discomfort symptoms. 2. Pathologic factors. (1) Bone and joint lesions: costochondritis, intercostal neuralgia, sternal fracture can also cause local pain and discomfort. (2) Reflux esophagitis: Reflux esophagitis can cause burning pain behind the sternum because stomach acid burns the esophageal mucosa. (3) Myocardial ischemia: myocardial ischemia due to coronary artery stenosis can cause insufficient blood supply, resulting in crushing pain in the corresponding area. The appearance of obvious pain in the middle of the sternum requires timely medical observation and standardized treatment under the guidance of clinicians.