• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

Orthostatic Intolerance as a neurological disorder

Andrew

Senior Member
Messages
2,513
Location
Los Angeles, USA
Just pondering something here. I have orthostatic intolerance. A cardiologist explained to me that it's caused by autonomic insufficiency in response to postural change. The result being the my body does not adequately adjust my blood pressure when I'm vertical. So if the cause of all this is a problem with my autonomic nervous system, wouldn't that mean this is (at least in part) a neurological disorder?
 

CBS

Senior Member
Messages
1,522
Just pondering something here. I have orthostatic intolerance. A cardiologist explained to me that it's caused by autonomic insufficiency in response to postural change. The result being the my body does not adequately adjust my blood pressure when I'm vertical. So if the cause of all this is a problem with my autonomic nervous system, wouldn't that mean this is (at least in part) a neurological disorder?

By definition, your doctor's explanation seems to presume an autonomic disorder as causal ("caused by autonomic deficiency"). However, there are competing theories regarding the cause of OI and perhaps distinct groups of patients with differing causes. The first alternative explanation to come to mind is low fluid volume. Fluid loading and increasing fluid intake are primarily efforts to increase volume. Vascular tone may also play a role. Fluid volume may be neurological but is not primarily autonomic and vascular tone may be autonomic but not necessarily so.