I've been using my heart rate monitor to keep an eye on my hr over the course of regular activity and doing mini versions of the "poor man's tilt table" test. I noticed that there were a few occasions when standing up did not produce a 30 point increase in hr. Usually it does and today I have not been feeling well and felt my heart racing and I noticed a 60 point increase on standing when I measured it. I was a little concerned about going in for the TT test and what if it's one of those days when I don't have a 30 point increase? I think that it rose 60 points in less than a minute is probably a good sign I have POTS, and most other times I've measured it's rose 30 points right away, but I'd like my official test to reflect this too. Does anyone know if it's possible to have "good days" with POTS to the point that it may not show up on a TT test? I have also been very lightheaded all day, I don't know if it's related. I'm not sure what set off my symptoms worsening today. All I can think that is different is PMS symptoms kicked in today, so maybe that's it. Also, my temperature is up more than normal at 100.2, I'm not sure if that could in some way relate.