The Prophet Muhammad (peace be upon him) said: "There is a cure for every disease. Whenever an illness is treated with its right remedy, it will, with God's permission, be cured."
Fiqh-us-Sunnah, Volume 4, Number 5C
Nu'man b. Bashir reported Allah's Messenger (may peace be upon him) as saying: The similitude of believers in regard to mutual love, affection, fellow-feeling is that of one body; when any limb of it aches, the whole body aches, because of sleeplessness and fever.
Sahih Muslim
Narrated Abu Huraira: Allah's Apostle said, "There is a Sadaqa to be given for every joint of the human body; and for every day on which the sun rises there is a reward of a Sadaqa (i.e. charitable gift) for the one who establishes justice among people."
Sahih Bukhari