We just went to Mayo in May and saw Dr. Fischer in the adolsescent clinic for my daughter who is 17. She was diagnosed a year earlier with POTS and had just gone through a really rough couple of months, as well as a permanent migraine that started at the same time. I asked Dr. Fischer about the sub-type POTS and testing for that, and he said that while some of his colleagues are in favor of it, he felt it didn't make a difference as the road to recovery is the same. He said he may feel differently in a couple of years if more research is done, but at this point that is how he feels. Lots of tests were done, and no reason for the POTS was found, other than it started with a virus, but that can't actually be proven with any tests, you are just telling them how you got sick one day, and never got better. But it is always discouraging to spend a lot of time and money and all of your tests come up with "normal", when clearly you are anything but. BTW, Dr. Fischer is just as delightful in person as he is on his YouTube videos, and overall the staff were super encouraging. We stayed at the Holiday Inn, which is a further walk than say DoubleTree, but still within the tunnel system, which at this time you will want, since it will be cold, and if you are like my daughter, you respond to cold negatively. All the Mayo hotels were a little pricey IMO. You can find some $99 deals. Or does anyone you know have miles they could donate for free nights? Interestingly, I read the book by Dr. David S. Bell, Cellular Hypoxia and Neuro-Immune Fatigue and I believe that there is a lot of information in that book that explains what is going on, but of course, there are no testing for that. However, Dr. Bell believes with research, there can be in the future. Hopefully, you are staying some place as close to the clinic as possible so it is a short distance for you to travel to your appts. Everyone at Mayo is super nice, and the minute we looked slightly confused as to where we were going, someone stopped and asked us if they could help. One time I saw the badge of someone who stopped and asked and he was one of the VP's of Mayo. You will never find yourself stuck, as even in the tunnel/corridors, people make sure you are OK if you even look like you aren't doing well. I was amazed at the service attitude throughout the Mayo system. Good luck and hope that you find some answers and help. No meds have helped my daughter, and she is currently having a weird relapse, with new symptoms, but she has had the shaking all day long. Exercise, regardless of the pain, is the only thing she has found that helps, and patience. But she is still not well, so not sure what the cure is! Take care and hope it is a great experience for you.