POTS
Postural Orthostatic Tachycardia Syndrome sounds pretty intimidating, I know. But it's better known by the acronym POTS.
Let's break that down:
Postural- When I stand up, my symptoms get a whole lot worse
Orthostatic- Kinda redundant, means "relating to an upright posture"
Tachycardia- My heart rate goes through the roof when I stand, and shoots back down when I sit
Syndrome- It's just a collection of symptoms, not necessarily with a root cause
How does it affect me? Well, for starters I'm on more meds than I care to admit (we're talking double digits). It also means that I can pass out- a lot. Without getting into too many specifics in this post, I have missed quite a bit of school, been in a lot of pain, and frequently can't get out of bed.
Hope this was a little bit informative. :)
@TCo
Hi @TCo !
Thanks for this thread ! 
Take good care for yourself !
I'd also like to add that it's causes dizziness if you don't eat enough or if there isn't enough salt in the diet. For me as well it causes morning sickness.
Thanks for mentioning my condition it's awesome to be recognised!
@TCo
@ElanortheFair
I totally agree!
I'd never heard of it before, I'm sorry you have to go through that. Thank you for making this thread, I learned something new! 
@Harieo
Thanks for taking the time to look at it! It's good to know people care :)
thank you for this thread !
Hi. I'm McKenzie and I've been dealing with a multitude of symptoms for over 18 months now. I see a cardiologist next month who specializes in POTS, and I'll admit, I'm terrified. I'm afraid more of not getting a diagnosis than getting one. I just want answers at this point.
I know this thread hasn't been posted on in a while, but just wanting to bump it back up. Fellow POTSie here! 
I also have POTS. I'm affected any time I change to a "higher" position (laying to sitting or sitting to standing). I also cannot bend down even slightly, which makes it very hard to take care of myself.