It's an awful test but it's the only way to diagnose something called POTS Syndrome, which I'm 90% sure I have...my aunt has it and we have the exact same symptoms. :/ I've tried blood tests, heart tests, and everything for three years but haven't found out what my issue is. (I have spells where I lose my vision and get incredibly dizzy and ice cold, etc. It happened once at your house a long time ago lol) So I think this it what it is. My test is scheduled for next Thursday now. :/