I don’t have POTS, and am on 2 different beta blockers (day vs. night), so my HR is rarely that out of whack. I’m glad they aren’t using that for a metric - I once routinely got to a HR of 180 walking, but not now that I’m stabilized on meds.
I’m 43, and I don’t have much weight cushion, either. I was really thin until I had to start meds for trigeminal neuralgia, which put 20lbs back on me, and I’m almost a good weight again. I’ve been sick for about 15-20 years, but had some of this all my life - I just thought it was how everyone felt, and believed that everyone passed out sometimes.