A persons ability to work depends on their own health issues and treatment plans. Many people live their whole lives without even knowing they are anemic.
Depending on the case I guess to some people it affects them in one way or another. I've always worked and I never had convalescence some for this causes despite having a severe anemia.
My baby doll Olivia had Achalasia and Anemia a few months ago, like in April she seemed fine but her esophagus was a little bad but that's okay I guess, now since its october she doesn't have achalasia anymore but she still Has anemia.