I am 19 age male. Height - 6' weight 54 kg. Some times when I am doing actions like standing quickly or turning 180� very fast causes to loose consciousness. It feels like I am given a high dosage of anaesthesia and my body has cooled down, specially the brain. It lasts just for 3-4 seconds, but that 3-4 seconds are really horrifying. But somewhere inside my mind is saying no boy you are not going to fall and continue your work. So inspite of getting unconscious I keep on doing the work. Can I know what is this? It doesn't happen always just 4-5 times. Is there anything I should include in my diet for extra vitamin or something and or any exercise? And is it a very serious condition/disease? Thank you.