R.R.
I just want to add that my daughter often GETS plasma, and usually ends up with a headache because it unbalances the electrolytes, etc. Reverse would seem to be true also. She also goes through this process called plasma-pheresis where they remove her blood, spin out the plasma, treat it and put it back. It gives her a headache too because of the fluid imbalance. Next time try to hydrate well ahead as others have suggested, and know that it is VERY much appreciated!