Ok.... Back :)
First, Welcome to HealingWell... but I'm sorry for the symptoms you are having :(
A great website for learning more about POTS is www.dinet.org. It's *overview* of POTS is spot on - well, at least for me it is! Here's a quote from their site:
Postural orthostatic tachycardia syndrome is defined by excessive heart rate increments upon upright posture. A person with POTS will experience heart rates that increase 30 beats or more per minute upon standing and/or increase to 120 beats or more per minute upon standing (Grubb, 2000). These exaggerated heart rate increases usually occur within 10 minutes of rising. (from www.dinet.org)
So - according to the above definition - and my own experiences - reading your symptoms, it really does seem that POTS is a definite possibility...
Obviously - I'm not a medical professional and none of us here can *diagnose*... but, from my own journey w/ POTS - all that you share sounds very familiar.
Re: your question - my symptoms aren't always constant nor predictable. Sometimes I jump up too quickly and feel extremely dizzy, blood pressure plummets, heart rate hits the roof, etc - and I've passed out a few times. Have almost passed out 100's of times. BUT there are other times when I can do the exact same thing (change in positions) - and be just fine.
My encouragement to you is to find a doctor that knows about POTS or is willing to research it out and help you.... My PCP was the original one to diagnose me; but, after having to move, I found a cardiologist that knew the basics of POTS - but also researched it out completely - and continues to be my treating doctor... There are medications that can help you manage the symptoms, if that's something you need. I know many other *tips* for managing POTS... if you have anything specific - please feel free to ask.
Take of yourself - and let us know what you find out or how you are doing.... --Tina
Moderator - Chronic Pain Forum
My faith and family sustain me even on my worst days... as well as my wonderful friends here at HW.
Health/Pain Issues - too many to list; feel free to e-mail me or ask on the board. Thanks!