BLACK OUT... Lights ON please :S

I almost got a black out on Monday's morning, not sure what exactly have causes this, but I would say, this could be quite scarely if its just strike on without any 'advance notice''. Its so sudden and you have no way to stop this black out, I simply just lost my consciousness, and cold sweats just rolled it down and I can feel my heart beat are faster and my ears are blocked from hearing. I'm not kidding, if you have ever encounter this, you know what I mean ya. Thanks God, the doctor said I'm fine, not sure if this is caused by the lack of sleep, cos I have been watching Heart of Greed, as recommended by Cuiyi. The drama is real good, don't miss this out, if you are a drama fanatics like me :D