Re: bruised sternum?
It's always wise to check with your doctor if you are having a problem with your health. Sternum pain may be due to a number of things, and self treatment may or may not help. Pain that is felt in one area may also be pain that radiates from another source.
So the best thing to do is have your doctor check it out and see if they can tell you what it is. Then see what can help.
Hope you feel better. I had a lot of bi-lateral rib pain last year that lasted 4 months, and still never got a definite diagnosis. So I understand how difficult it can be to live day after day with pain.