Plasma is a very harsh thing to donate in my mind. I've never had a problem giving blood and I have been doing it for a very long time. However when giving plasma they return everything to you but the plasma, and they replace it with some freakishly cold synthetic stuff. Giving it felt fine, but watching fake blood travel up a tube and steam into your arm where you instantly feel cold is just horrid. BUT!! Donate anyways. Other people need it.