So, I have had everything from EKGs to EchoCardiograms since I was 15 and doctors have found nothing wrong with me. I have had on and off cheast pain on and off since I can remember. It generally has revolved around taking some kind of ephedra or diet pill. Yes, I understand they are bad for you. Long story short, I am 26 now, and have been having some pretty bad cheast pain for a couple of months. It feels like significant pressure in my cheast (yes, left side), sometimes I can rub my cheast to try to help elleviate some of the pressure, it occasionally hurts bad enough it's in the same area to my side or in my back. My left arm has been hurting a lot as well. On the right side of my arm next to my body, lower than my shoulder, and in my forearm. The pain gets bad enough it wakes me up in the middle of the night. I also have shortness of breath occasionally as well.