Ever since I woke up this morning, I've had these on-and-off feelings of lightheadedness and trouble with my balance. I noticed it when I was half-asleep and crossing my room to snooze my alarm clock, and the 3 other times I did that before i turned it off and finally decided to get up. I chalked it up to only being half-awake... but it's continued. Mostly if I'm sitting down, it's not too bad. But if I go to stand up quickly, I have to catch my balance... turn around too fast... same problem. This is NOT something I've ever experienced before. Does anyone have ideas as to what might be causing it, or what to do about it?