I think Dr. Peli nailed it.
but ya, it sounds like it might be teh carp.

I've had problems with carp before, I usually just have to lay off the mouse for a few days and it clears up. But usually it hurts my wrists.
Could just be a pinched nerve or something too, maybe I slept on it wrong.
Or Sups might be on to something too, all my fat rolls may be cutting of the supply of blood.