So glad to finally see a study on low blood volume...It seems like such a fundamental problem yet studies are rare. Small study but very good to see. Hopefully more will be coming
I went down the dysautonomia/POTS route a couple years ago when I passed out on a tilt table. After doing more tilt tables at different research centers, I no longer would pass out on them. I think 2 things contributed to me passing out on the first one. First of all, I was not allowed any fluids past 9:00pm the night before and the test was at 10:00am the next morning. I also was very symptomatic at the time of the first tilt table. The other tilt tests were done during the day and there was no restriction of fluids.
No doctor could really put their finger down and say I for sure had POTS, because I was riding that fine line of an increase in heart rate of 30bpm or more. I was always around the 15-25bpm range.