I recently experience the following episode: I was lying on the bed and my daughter asked me to look at her as I was upside down. While on my back, I layed my head off the edge of the bed. I was in that position for no more than 10 seconds when I began to feel slightly uncomfortable. After about 15 seconds in this position, I sat upright and was immediately sick. I was nauseas, dizzy, and vomited each time I moved (because of the dizziness). I remained in this condition from 4:00 p.M. Until the following morning.

I didn't see a doctor because I figured it would pass, and it did. But I was extremely concerned (and still am) that I may suffer later from something as a result of this.