Here's my RSI (repetitive strain injury) story:
Two months ago, while I was typing, my wrists started bothering me. It was just a slight pain/discomfort that I had experienced many times before whenever I typed too long without a break, and usually went away after I took a break for a couple hours. So I wasn't concerned and continued to type. Soon afterwards the tingling in my wrists got more intense, and I also started to feel a dull burning sensation right under my wrists. It wasn't really painful, so much as it was uncomfortable and annoying. But it was bad enough that I couldn't continue typing. I still wasn't worried in the least, of course, since I had experienced this many times before in a lesser degree, and I figured it would go away with a night's rest.
Well, now it's two months later, and my left wrist is currently still burning, and I'm typing this by pecking the keys one-by-one with a pencil. I'm a piano major, and the semester begins in about a week, but I'm not able to play more than 15 minutes at a time before my left hand (which got it worse) starts burning up. Even less time than that if I'm playing Bach (who's equally unforgiving on both hands).
I'm terrified. I think as RSIs go, mine is pretty mild--it's not painful or uncomfortable enough to be distracting most of the time, and I can do everything comfortably except type or play the piano. But it's just not going away. I still haven't seen a doctor about it.

(But I will soon.)
Does anyone have any advice or insights into what form of RSI I have? Or (God forbid) have stories of their own to share? RSIs sneak up on you. I hope my story conveyed that and helps some people avoid injuring themselves.