I have pain in my upper back the area where the bacl of the chest?!

I have pain in my upper back the area where the bacl of the chest?

I have pain in my upper back behind my chest..When I stand some it hurts..When I strecth my back bacwards I feel it more also kind of short breath..I don't know what to do?

I know that feeling quite well. I have scoliosis, (spinal curvature) so I deal with muscles that are always lengthened and shortened. If your pain is the same as mine, and it sounds like it, then you may have pulled a muscle or even have compression on a nerve. Try a good massage therapist, full hour to hour and half. If you still have the pain a few days later, try a chiropractor. Get a referral as this profession has those with natural skill. Acupuncture has worked wonders for me. My chiro does both. Good luck