John,
Before my first relapse of symptoms
and getting sick, I worked at a hospital
and was
donating blood. One time, I could not donate because I was slightly anemic.
The other times though, oh boy, during and after giving blood I felt like I was in la-la land, extremely dizzy, blurred vision etc.
I stopped giving blood because of this. Now, I know this was almost like an exacerbation of symptoms.