Is Low Nocturnal Recumbent Bp A Surrogate Marker For Low Blood Volume?

[Annaliese]

Since direct blood volume measurement is not available to me, I am looking for a potential surrogate marker for it. Any ideas? I thought perhaps low nocturnal recumbent BP might indicate overall low blood volume in that the sympathetic nervous system whilst asleep is depressed (ie so no chance of a compensatory symp effect if blood vol is low). What do you think?

[POTSMama]

I can't answer your question, but I do often have low BP at night often, except for when I have occasional episodes at night where it is flopping from low to high and back again. My BP is higher during the day. But I am pretty sure my POTS is hyperadrenergic, so that may be a factor.

Carol

[HopeSprings]

This was a little over my head, but I have low BP at night while laying down. It's my lowest of the day, at around 75/39. However, I think everybody (sick or not) goes lower at night and/or while laying down. Are you saying low numbers somehow translates into low blood volume? Can you explain a little more (in easy to understand words) because your thought sounds interesting.

[yogini]

I agree with Naomi, everyone's BP goes down at night. I don't think it's a marker for low BV. It's interesting because many of us with normal BV and even normal BP benefit from fluid and salt loading and meds like florinef, which essentially increase BV. so I think it's hard to know if you have low BV unless tested.

[Annaliese]

Thanks for your responses guys. I know that most peoples bp drops when asleep but what im talking about is VERY low BP. For example if i dont take florinef, my BP goes so low that i develop symptoms of hypoxia (my legs start kicking). I also get freezing limbs and pins an needles and my heart periodically goes into tachy. With the florinef, none of this happens. Im thinking that during the day, my symp nervous system is going into overdrive trying to correct for the low blood volume ( i have lots of symptoms of symp ecxcess) and as a result my bp is normalish (except when standing). So at night when my symp nerv syst activity is lowered, it seems sensible tht there would be a big drop in bp (rather than a small one).

[julieph85]

Thanks for your responses guys. I know that most peoples bp drops when asleep but what im talking about is VERY low BP. For example if i dont take florinef, my BP goes so low that i develop symptoms of hypoxia (my legs start kicking). I also get freezing limbs and pins an needles and my heart periodically goes into tachy. With the florinef, none of this happens. Im thinking that during the day, my symp nervous system is going into overdrive trying to correct for the low blood volume ( i have lots of symptoms of symp ecxcess) and as a result my bp is normalish (except when standing). So at night when my symp nerv syst activity is lowered, it seems sensible tht there would be a big drop in bp (rather than a small one).

I think you are spot on with this Annaliese! My only argument would be that I dont' believe low BP can be a marker for the blood volume even though that would be nice! I do think that a narrow pulse pressure when laying down as well as standing can be though. My pulse pressure gets very wide when I lay down but like you my overall blood pressure gets very low as well, especially at night.

[Annaliese]

Julie, i see where youre heading with that argument. My pulse pressure is ok when lying (at keast i think, i cant get it often because its too low). My pulse pressure when standing is terrible (15).