From what I understand with fibromyalgia, you have tender points throughout the body (I can't remember how many) and it can effect the muscles, tendons and joints. It does not effect internal organs. This is not the same as RSD. As alt stated, RSD is with the sympathetic nervous system. I understand the pain is much different and worse with RSD. I have had RSD for 20 years now, but not fibromyalgia. I saw a Rheumatologist and he pushed on those tender points and I didn't react to any of them. He said I would've had to react to at least some of them to have fibromyalgia. My mother-in-law has fibromyalgia and suffers with it. All those tender points are tender on her!!

While there are similarities, there are also some big differences.

That's my two cents
Nanc