The skin heals, the wound is repaired. Even in the worst of circumstances against all odds, the body will try to heal and survive. It can heal itself of any illness with the necessary work. The problem is to know what the necessary work is. Illness and disease are states where the body is off balance.
Healing is the return to health, a return to balance.
This also means you can trust your body. The messages it give you in the form of pain or illness are signals that something is wrong. It needs attention. The body is not a capricious enemy that will let you down given the slightest opportunity. You can learn from every illness.