Hmmm...I guess the worst experience for me is when I had to get a blood test done and the nurse couldn't find a vein (I have deep veins and don't give my blood up easily. Takes the folk in the in blood bank 10 mins to find one) so she sticks it in the tiniest one nearest the skin....needless to say the last thing I recall is saying...my arm's gone grey.....at that point I hit the deck apparently.
Or maybe it could be multiple blood tests and scans for 6 years until you have a name for the condition you have (I'd say what it was but it's kinda personal
). And why 6 years? Because my last doctor refused to do one tiny little test that would have made my life so much simpler. Just can't find the staff these days......