Where To Find the Cause of Illness

Recently one question is occupying my mind and I cannot find an answer for it. Why do people get ill? Do the problems with our health mean something more then just a disease? I mean not just to get a cold but even this could have some metaphysical reasons(that are some that go beyond physical explanations that we all can understand). Nearly every physiological disease happens because of our body and mind connection. But how does it work in detail and why do some people get cured and others not? I try to find out deeper reasons for that why do people get ill if they have not been determined jet. But I am pretty sure that the answers exist and it will only take some time to find them. Only imagine how wonderful it would be to live long, healthy and happy life and to help other people. To clue this mystery has become my fixed idea. I also understand that there are things in this life that are past our comprehension and we should accept them as they are. But something makes me believe that is not the case.