I have been ill at least 20 years. But over 39years ago, I had to have a very serious surgery to my middle ear in 1985. The doctor thinks my vestibular nerve was damaged by a virus. So that was when I was about 20 years old. Tis goes back a long way. I started needing naps at about age 30. After a move across the country, I got very ill and kept getting worse. After loser docs, I finally found good ones. I was for b12 level and other tests. My b12 was barely on the scale. SO low, I was given shots and improved a lot. I was guided with diet and supplements. I had not been eating red meat, this thinking that was good....ha I never did that again. Epstein Barr is what I fight with supplements. I can't really say it was gradual but I guess it was a bit gradual. Once I moved it was BAM! Fast. POTS began after a surgery and also an antibiotic before that. A few months later I was in a grocery store, unable to walk all of the sudden . It was so strange to feel like I would faint. This happened a couple of times, small things happened, then on our anniversary three years ago, my autonomic nervous system stopped working. I now know it is autonomic neuropathy. I am slowly healing the nerves with supplements and no sugar,bad carbs, gluten... slow but steady healing. My hubby and I are happy.