I am a 27 year old male, 5'9 159 pounds. I have had an extensive workup for heart disease - stress echo, ekg, and an ER workup of ekg, blood tests, chest xray x (4). I have had about 6 normal months since and have been running every 2 days about 2 miles and get a few skipped beats that are sharp and painful..but no other symptoms, so I just accept that. What bothers me is that I have a deep pain that can be sharp and dull under my sternum (doesn't spread to arms or jaw) that seems encouraged by poor posture or leaning forward and moving my pectoral muscles. I have no difficulty breathing. There was no heavy lifting to bring this on. I tend to wake up in the middle of the night from the pain (not necessarily severe) and have a little nauseation or stomach upset(the advil?) My GP believe it is costrochondritis. I agree the symtoms sound the same but I have no reproducable tederness by pressing on the sternum. What other muscles, organs, vessels, problems could be involved given a normal heart>? And could it still be costrochondritis without the reproducable tenderness in the sternum?