i do not know what caused my pots, but i am wondering if it is vascular because about a year ago (when all this started) i had what i believe to be a mini stroke. I was just sitting on the couch doing homework and it felt like something popped in the back of my head. my vision turned upside down and the room started spinning, i went numb and tingly on one side of my body, got a real bad headache, and became extremely tired. i fell asleep for five hours and when i woke up i was still so dizzy that i could not walk in a straight line. anybody else experience something like this? does it sound vascular? if so who does test for vascular problems?