introspectif:

Islam on Illness

I visited the Prophet during his ailments and he was suffering from a high fever. I said, “You have a high fever. Is it because you will have a double reward for it?” He said, “Yes, for no Muslim is afflicted with any harm but that Allah will remove his sins as the leaves of a tree fall down.” [Sahih Bukhari Volume 7, Book 70, Number 550] More here.