For the past two months I've been lightheaded many times as I stand up from bending or crouching. Once I fainted on my way to use the bathroom in the middle of the night but figured I somehow just fell back asleep on my feet. This morning I passed out after a feeling of lightheadedness as I stood up from squatting down next to my 5-year-old daughter. My 9-year old said my eyes didn't shut, and they were moving back and forth fast, then they rolled up toward my eyelids. (Freaked her out, needless to say.) I was only out for a couple of seconds, I think. I have no memory of falling, nothing. When I came to, I felt kind of buzzy, my tongue and face were sort of tingling. This was not as I got out of bed, but was before food or drink, etc. Any ideas about what is going on? I'm new to this.