I have a problem where I get really dizzy and pass out a lot more than the normal person. It's happened so many times that I can sense when it's about to happen so I'll go lay down for a while. It happens the most when I'm in the heat for a while or dehydrated from being sick, but it also happens at seemingly normal times like when I'm getting on the bus. I am a healthy 21 year old female who eats healthy, drinks water constantly, and exercises. This has been a problem the last 2-3 years.