I'm an active 14-year-old girl with no known illnesses. The only problem is whenever I am to yawn and stretch I feel dizzy and zone out. It has been like this for the past year or so but this month it seems to have gotten worse. For example: I was standing at the top of the stairs when I yawned but when I opened my eyes I was lying on the floor and temporarily had no recognition of what I had been doing a couple of minutes before however, I knew I had fallen since I felt a pain in my side where I had fallen and hit the banister next to me. I am not sure if this is serious or just a natural thing that just happens to some people. Does this happen to any of you and do you know how to stop it?