Once I had a biopsy because the doctor didn't know what was wrong with my leg, and probably because of the numbing (I don't get along with needles... they make me sick) I felt really sick afterwards. I got nautious and when I stood up my head hurt and I couldn't see. So yeah... and sometimes my head hurts a little for a while and then my vision just kinda turns grayish for a few seconds... it's sort of random. I know it's not really the same though...