For the strangest reasons I have the tiniest veins (so says my a anesthesiologist when he was looking for my veins - not thru the naked eyes mind you, but from this thingymajiggy machine).
It usually takes a couple of jabs before my veins at my arms could be located, causing multiple bruises as an indication of attempts.
Today, it was on the first attempt - my lucky day, says the lab assistant.
However, the bruise is as big as a one dollar coin (or dua puluh sen coin).
This is how drawing blood from me is like.