I have seen lots of folks posting about their problems with POTS (postural orthostatic tachycardia syndrome). I rarely see folks posting about NMH (neurally mediated hypotension). I'm starting to get curious - is this just a coincidence or is there some reason behind it? My understanding is that POTS and NMH are two different forms of Orthostatic Intolerance (see http://www.cfids.org/about-cfids/orthostatic-intolerance.asp ) and that a patient can have either one, or the other, or both. Also, I believe that within the POTS category there are different forms (but I have not read as much about that). So, why do more PWCs talk about POTS on these forums? Is POTS a lot more common than NMH in people with ME/CFS? Or are people just using POTS as a "catch all" phrase for any symptom caused by orthostatic intolerance? Or maybe POTS is an easier diagnosis to get? I believe that POTS can be diagnosed after having the patient stand still for 5-10 minutes and measuring the increase in heart rate. Whereas a diagnosis of NMH pretty much requires a tilt table test because the drop in blood pressure is delayed. It may take 35-40 minutes before the BP drop happens (although symptoms may start within 4-5 minutes of standing). I've had two tilt table tests and the severe, sudden BP drop happened after about 20 minutes on the first test and after about 30 minutes on the second test (no isoproteronol or other drug was used to induce the BP drop, just standing still on the tilt table was enough). Anyway, I'm just wondering why there are more discussions about POTS than NMH. I do remember at least one person who has posted about NMH but not a whole lot of folks have mentioned it on these forums. Anyone out there want to hazard a guess?