Although I can’t be certain (your doctor is the one to ask, certainly), it sounds like you fit the “idiopathic POTS” category. They are not ruling out early neurologic causes, but it looks doubtful because the tests are negative. I remember at Mayo, my result said that ‘all autonomic testing, except for the tilt table test is normal.’You may be caught in that black hole that we were in — no one really understood what was going on. 🙁 Please tell me you have a copy of The Driscoll Theory? It’s written just for us!