Injuries and diseases on champions

One of the champions I hired was defeated in battle.  After the battle he was still alive, but had a "broken nose" that downgraded one of his stats.  A healing spell didn't seem to fix it.  The same thing happened a bit later in another battle, and this time he had caught a disease that again downgraded one of his stats.  How do you go about curing your champions?  Are there spells or potions that do it?  Thanks.