THey look at your symptoms to see if it fits. The second I told my doctor that I had an accident with my feet and my feet feel like their on fire he said it's probably RSD. I went to 3 other doctors to confirm it and they all came with that conclusion.

Pain is the other symptom that I have but there are many others. There's no test to do that can show that you have it. You've had enough tests you don't want another i'm assuming.

I had 3 nerve blocks that didn't work but EVERYONE is different. I didn't educate myself about RSD which I should have done before doing any other the things I did. I would research whatever it is that they want you to do.

Good luck to you!!!
Heather