There are few physicians who can or will diagnose Pure Autonomic Failure. It is essentially a diagnosis of exclusion--that is, when all relevant tests are negative, PAF is considered a likely cause.
My diagnosis was made by a very caring young physician on the basis of a long history of all kinds of problems diagnosed over my lifeime by various specialists and numerous print-outs I took him from the internet. One of the problems with getting a diagnosis is finding someone who will stick with you and put all the specialists' findings together.
I have many of the same symptoms you have, but no kidney problems, and I never passed out. My legs would collapse after walking about 30 feet if I had been sitting down for some minutes before walking. I would be too dizzy to even hold my head up. I ended up in an ER 5 times before I got a diagnosis of Neurogenic Hypotension. In researching this term I eventually found my symptoms described perfectly in several scientific articles. This was about 5 years ago. Last week I searched again and found many more articles, so I would advise you to just start looking under the term Pure Autonomic Failure. It is sometimes called Primary Autonomic Failure. There is a PAF that is caused by diabetes and one that you inherit, called Familial PAF. Neither of these applied to me, so I have Primary Autonomic Failure.
Although my family doctor and I knew what I had, no one else in the medical community believed this diagnosis, since it had not been diagnosed by a neurologist. I saw 3 neurologists who had never heard of PAF, including two at the University of Virginia. However, the last one I saw was willing to write that I had autonomic disorders of several systems, and since then I have told the many new specialists I've been referred to that I was diagnosed by a neurologist at UVA, and they accept this.
Whenever I see a new specialist - and I've been referred to many, as I'm sure you have- I now take a printout from the internet that describes how his specialty relates to PAF, as well as an overall description of the disorder. So far, everyone I've seen has appreciated the information and added it to my chart and their reading list.
So, my advice to you is to research, research, research or get yourself to one of the few centers referred to by Heiferly. I opted not to do that because of travel expense and the invasive testing that they use. And I had this wonderful Dr. Young, who was willing to listen and read and put everything together for me.
The Vanderbilt site has links to many articles and forums and should be a good place to start.
Anne
***@**** If you email me use PAF in your subject area
The best advice I can give, considering how complicated your case seems to be, is get to one of the "big" hospitals if you possibly can. Mayo (Rochester), Cleveland Clinic, and Vanderbilt all do evaluations for autonomic disorders routinely. I'm not sure what other hospitals do; those are the main ones people talk about on dysautonomia support websites.