question: i am a 45 year old female. healthy or at least i would like to think i am. and what has been happening is that whenever i start exercising or get on the threadmil, i start getting lighthead and feel like i am going to faint. after it happened a few times, i went to do a stress test and they put me on the threadmile, and it was happening again and they told me that my blood pressure was shooting down.... except they werent sure what was causing it... but it only happens as i work out...