I just watched the itachi arc, it was ok, but why wasn't his disease featured, since it's a pretty significant thing in the life of itachi, they should've at least dedicated a bit of time on that.
Dunno if desease but I think tobi mentioned (when talking to sasuke after sasuke vs itachi) that itachi knew his death was coming so he used medication to keep himself alive just so he could fight with sasuke. Granted, it was due to him using his mangekyou to often or something.He had a disease?!? When?
At some point, Itachi contracted a terminal illness. He kept himself alive through the years with medicine and sheer willpower so that he could live long enough to die by Sasuke's hand