Hidden pain in the middle of the sternum should beware of sternum fracture or inflammation of rib cartilage, digestive diseases, angina pectoris, heart attack, respiratory diseases, blood diseases and so on. 1. Sternum fracture or inflammation of rib cartilage: Sternum fracture caused by trauma or inflammation of cartilage at the connection between the sternum and ribs can be manifested as pain in the middle of the sternum. 2. Digestive tract diseases: such as gastric acid reflux, stimulation of the esophageal mucosa, resulting in esophagitis, esophageal pain due to inflammation stimulation, such as pain location just after the sternum in a section of the esophagus, can be self-conscious about the middle of the sternum hidden pain. 3. Angina pectoris, heart attack: patients with angina pectoris or heart attack will have squeezing pain at the sternum position, and at the same time, there is a sense of oppression, chest heaviness and other symptoms. 4. Respiratory diseases: when respiratory diseases such as lung infection or bronchitis cause severe coughing, it will also cause pain in the middle of the sternum. 5. Blood diseases: When there are blood diseases such as leukemia, the abnormal proliferation of cells makes the pressure in the bone marrow cavity increase, so there will be a dull pain in the sternum. Those who cannot relieve the dull pain in the middle of the sternum should go to the hospital for further examination to clarify the cause of the disease, so as to take corresponding treatment measures.