in Neurally mediated hypotension the blood pressure goes down.
with Postural orthostatic tachycardia syndrome, the heart rate goes up and the blood pressure also goes
up in an effort to compensate and provide oxygenation to the vital organs.
Now some people with autonomic dysfunction can also have both.
Sorry I was responding from a post from
@leokitten on the first page
Having NMH and POTS/OI means you have hypotension most of the time, and with POTS/OI this is thought to be due to low blood volume. Yes when you stand up your heart rate and blood pressure shoot up in order to provide adequate blood pressure and flow to the brain, but this is merely to try and compensate for the fact that blood pressure and volume are actually too low.
So knowing this it doesn't explain at all why sGC activators/stimulators which are potent
vasodilators are causing significant improvement in symptoms for a lot of people with ME/CFS. You would think that this would make people with low blood pressure and volume way worse.
Or it may be that these drugs are only helping people in my subset. ME/CFS caused my blood pressure to suddenly go from normal to prehypertension range and I never got OI or NMH. The raised blood pressure I found was due to two things, one being SNS activation (which Fluge/Mella believe is due to low NO).
The other is due to
hypervolemia not hypovolemia. I've also had many episodes of POTS but I challenge people to assume this is due to low blood volume. I had my blood volume measured by Daxor (the most accurate method) three times and all three times I had severe hypervolemia due to highly elevated plasma volume not red blood cell volume (so no polycythemia).
This is why I challenge PWME to not draw immediate conclusions if you have POTS, it doesn't always mean you have low blood volume. Very few people have actually gone and measured their blood volume with Daxor and I think it's very important to do so to verify your blood volume status and not to just draw conclusions based on symptoms.
In addition to having hypervolemia ME/CFS caused me to have bradycardia all the time except during those episodes of POTS. And this makes complete sense, hypervolemia causes bradycardia. I've also written up a thread here on PR to show people that the polyuria we get in conjunction with low aldosterone and vasopressin/ADH are in many cases a natural compensatory reaction to the fact that we have gone hypervolemic and our bodies are trying to desperately get rid of the excess water in our blood. A lot of people get polyuria and measure aldosterone and ADH and see both very low and then think this is causing low blood volume when it's not always the case.
These vascular changes caused a lot of other symptoms for me, rapid global muscle and tissue loss, abnormal hair loss and accelerated greying, bulging varicose veins. You would think with hypervolemia this wouldn't happen but it does and this all points to poor vascular dilation and tissue perfusion.
So to me it seems like many of our symptoms can be explained by the fact that we have these vascular problems.