I was wondering how donating blood would affect my CFS. My sil just got dx with leukemia and is haveing a fundraiser in a couple of weeks. She is going to have the blood mobile there and I was kind of interested in donating but my husband said it would send me back into a flair if I am better by then. There is no way I could do it right now as I can hardly get off the couch. But has anyone donated before and how did it affect you?