blood tests won't *confirm* epilepsy but they can show indicators of it, and they can confirm possible reasons for a collapse other than epilepsy. Getting rid of more blood for tests isn't an issue - they only take a tiny amount, and you've already replaced that which was taken. However you may be advised to not donate any more, which is IMPORTANT, not just for your safety but for the safety of the recipients of the blood, not to mention everyone at the donation centre - they are there to get blood out of people, and if someone keels over into a bed/a table with needles on/half a dozen other patients, it causes a situation they could do without. Getting the blood tests "wastes" a few minutes of NHS time until they tell you what's up and either fix it or start controlling it. Not getting the blood tests, and continuing to collapse, takes up time for and is upsetting for: -you -your family -your friends -any passers-by who see you hit the deck and try desperately to remember their first aid -this includes your "lovely new friend" who has completely disrupted her day - next time you might not be so lucky -and whoever she was going to see that day -emergency doctors -an ambulance crew if a passerby calls 999 -whoever's doing your laundry and trying to get out the stain of whatever you've landed in enough yet? Go get checked out before it becomes a real problem. (I'm not having a go, I pass out too)