When i stand up quickly sometimes, my vision fades black for about 3 or 4 seconds abd i grt a little dizzy. I eat and drink very well as well as getting 20 hours of exercise a week. I am 16 years old and just recently it happened while i was walking on wood floors at my house. I fell down and hit my face and knees on the wood, bruising my lip, cheek, and knee caps. I have really good reflexes but my arms didnt catch me. I get this sensation
about 3-5 times a week and i wasn't concerned about it until i fell. Is thid normal? Will it ever go away?