I get these spells where I m fine one second, and the very next i m overcome with fatigue and dizziness . When I m standing and it happens, my knees buckle. My mom saw me while I was having one and said my eyes got really red and closed about halfway. Within seconds, I felt better and she said she could tell because my eyes got white again and they opened back up. What could this be? We ve tested blood sugar , blood pressure , I ve had ct scans and there are no tumors or anything in the brain.