Hi. I used to be anorexic but am doing much better with my nutrition now. I weigh approximately 115 lbs and am 5' 5" and 18 years old and female. I have, for a long time now, gotten dizzy often when standing from a seated or lying down position. This is accompanied by a blacking out of my vision and a feeling of swaying. Sometimes I need to sit back down. Lately, however, this has been accompanied by body jerks while my vision is gone, causing me to need to grab on to a wall or something to steady myself. These jerks feel pretty severe to me. Is this a big problem? Is there something I need to do differently? I am athletic and in very good shape. I run 6 days a week.