For me at least...the pain is constant and all the time. It's a deep, burning pain that is all the time. When something touches me...that pain is like someone dragging a hot poker or a blow torch across my skin in those areas, and this is on top of the constant burning pain. When cold touches it..similar thing but evern MORE intense (which is saying something). Weight bearing and moving the RSD areas also causes pain on top of the constant burning...but less than the way it flares with cold...but the TENS unit helps me enough to tolerate walking a little and to do my physical therapy. Weather changes also flare up my pain...and sometimes it flares for no apparent reason. With all that against me...that's why even things that help just a little bit are welcome. I'll do just about anything if it will give me some sense of normalcy in my life.