Hi Chelle, I have both as well. Aren't we lucky?
Sometimes I simply can't tell which one is causing the pain, to be quite honest. The fatigue could be both. Since I started taking Amitryptiline (someday I'm going to learn how to spell that consistently) I'm getting better quality sleep and so the fatigue isn't as bad. Tylenol Arthritis does bupkuss for me - zip, zilch, nada - unless I take four at a time, which I don't do often as it's bad for you. Sometimes, the Celebrex helps the pain, sometimes it doesn't. When it doesn't, the only thing that can make my muscles relax is pot.
I have found (egad I'm almost afraid to say this) that exercise helps both - in muscle relaxing terms and in terms of keeping my joints moving. But that's me.
Oddly, the dx of AS came very easily for me (once I started looking); however, the dx of FM has not. One doc says yes, the other says no. The majority say yes, so I'm going with it.
Hugs,
