What should I do for sternum pain?
Sternum pain warrants prompt medical evaluation at a hospital, as it may stem from the following causes:

If there is a clear history of trauma, sternum pain is typically attributable to sternal injury or soft-tissue injury in the sternal region; treatment may include oral or topical analgesics targeted to the affected area.
In cases without a definite traumatic history—i.e., unexplained sternum pain or tenderness—the possibility of hematologic disorders should be considered, such as anemia, aplastic anemia, or leukemia. These conditions require specialized, disease-specific management.

Pain localized behind the sternum generally suggests esophageal, mediastinal, or cardiac pathology—for example, gastroesophageal reflux disease (GERD), esophageal cancer, mediastinal tumors, angina pectoris, or myocardial infarction.
Pain on either side of the sternum is commonly associated with costosternal joint inflammation or costochondritis. Therefore, any sternum pain merits timely medical consultation and evaluation at a hospital.