[Doczilla]

Understand that I'm trained more to look for things that can kill you rather than that which is most likely, and therefore may be seen as an alarmist.

I agree with the others as far as what is most likely at the root of the problem, but there are a couple of red flags here. You describe cramping/early fatiguability of your hand and arm with activity. This suggests a vascular compromise to the arm rather than a nerve problem. Parasthesias at night can be caused by vascular insufficiency as well as nerve impingement. Here's the thing: the nerves in your arm come from C5-T1, not T5/6, so if there is a nerve problem with the arm, it's not where you are describing your pain. The little hairs stand up on the back of my neck when someone says back pain radiating through to their chest with activity.

Not knowing your family history or having examined you, I think you need further workup. I'd go to an internist (internal medicine specialist) before I'd go to the orthopedist. If your pain has only been going on a few days, it's worth a trip to the ER for a chest x-ray, EKG, and enzymes. Otherwise, call the internist's office, describe the above symptoms as I have, and they may find a little room in their schedule for you.

'zilla