Hi Renee, I do use a TENS unit and have had it for several years. It really works best for me when I feel my muscles tighten up in my shoulder and neck area ( RSD started in my left arm). It is good because of the many levels that you can set it on and it can be worn on a belt clip. If your insurance will cover it I would give it a shot. It is easy to use, non invasive and can be used to cover the areas that you need it on the most. My kids have even borrowed it for when they get a pulled muscle and my son used it in his shoulders after a laproscopic surgery to help with the pain from all the gas they pump into the abdomen. I really wouldn't be without mine. Lisa