I'd like to have him to deal with fatigue, weakness, various pains, probably fever (y'know, pretty things ^^). My first choice was some type of cancer, leukemia perhaps, but my researches (Wiki, Google; cancer, leukemia, treatment) had somewhat confusing outcomes, regarding the actual treatment.
Basically, provide me with the name of a disease which fits the requirements, so I can research it. Pretty please?
EDIT: Okay guys, thank you!! XD I have quite an array of maladies now to choose from. You're awesome. ^__^