I'm a researcher in bioethics - specifically I'm interested in the nature of health and disease. But, from a philosophical perspective, which means I am trying to come up with a definition of health and disease. For example, the World Health Organization defines health as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity." But, I disagree, because I think this definition confuses health with well-being. A person can have health and still not be flourishing as a human being - if they have a job they hate, or their spouse recently died, etc. And a person can be flourishing while lacking health - if they are sick but have a good attitude, many friends, a good job, etc. So, what is health if it is not well-being? That's what I have been trying to figure out.
My connection to dysautonomia - I have had an irregular course of illness. I was diagnosed with POTS at age 18 when I complained about feeling weak in my legs during cross-country practice and feeling dizzy. 10 years later, I visited Julian Stewart's lab in NY, and they couldn't say much more than that I get blood pooling in my legs. I've never had difficulty standing. I've run half-marathons (as recently as summer 2016), and I am in cardiovascular good shape. I mostly struggle with being tired and brain fogged. I feel worse on cloudy days, hot days, and days when I haven't slept well. On a day when the barometric pressure is high, and the temperature below 70, I may feel really good! I feel foggier in my head for 24-48 hours following intense aerobic exercise. I get pain in my legs and weakness in my limbs if I stand still for more than a short period of time.
I find that lying down periodically, drinking lots of water, and avoiding over-exertion helps the most.