Anyone else feel like they almost fainted?

Sh
I was standing up at work today and all of a sudden, mid-sentence, my vision got blurry, my ears started ringing and I thought I was going to throw up. I made it to the bathroom and basically sat on the floor for a few minutes while it passed. It happened another time after that with a few dizzy spells since.
I went to the doctor and everything came back normal, including my blood sugar. Has anyone else felt this way? What was the cause? How did you make it stop?