I'm 14 and I have this weird sort of thing. My sternum seems to extend out about an inch than what it should. My friends ask whats wrong with me and I cant tell them because I dont know. Going to a doctor is a good idea, but I would like to know what you think it could be. I dont have any breathing problems or heart problems. Please give me a clue to what this could be.
Thank you.

Not sure - perhaps it's nothing and just something you notice and so friends now ask? Do you have particularly long arms, legs, and fingers in comparison to the rest of your body? Any curvature of the spine?

It's possible that you may be describing pectus carinatum, a rare genetic variation. Google it with "pectus carinatum" and "emedicine" and you'll get some good information.