Hidden pain below the sternum may be related to heart disease, digestive system disease, respiratory system disease, chest wall disease and other reasons. 1. Heart disease: if angina attack occurs in patients with coronary heart disease, due to myocardial ischemia, vague pain below the left sternum can occur. 2. Digestive system diseases: such as reflux esophagitis, acid reflux, hiccups, belching and other symptoms, accompanied by esophageal mucosal swelling, congestion, the phenomenon of hidden pain below the sternum. 3. Respiratory diseases: such as pleurisy, massive pneumonia, under the action of inflammatory factors, there may be vague pain below the sternum. 4. Diseases of the chest wall: such as fracture of the sternum, ribs, costochondritis, etc., can also cause vague pain below the sternum. It is recommended that people with vague pain below the sternum go to the hospital in time to clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor.