Oh man...I know this is not what you want to hear so I hope someone else can chime in with a better answer. But...I was basically told that if there was no OTHER cause for the pain and symptoms then it was RSD. That meant LOTS of appointments with different specialists to rule out a bunch of things that COULD cause my pain and symptoms before I got the RSD diagnosis for those areas. It took months but it was worth it because if it had been something else it would have been important to get the right treatment. Hope there is an easier answer...but I don't know of one.