We used to believe, truly believe, that the earth is flat and that we would fall over the edge if we went too close. We also believed, truly believed, that we were at the center of the universe. Heck, we even burnt someone at the stake for saying otherwise. We believe other things now, but they are as firmly embedded in our minds as those from earlier times we now call silly. One of them concerns self-healing. We currently don't really believe that we can self-heal, or let's say that we only believe it under certain circumstances (which makes no sense; it either works, or it doesn't). Usually we quickly run for outside help, doctors, pills, tests, and so forth. But think about this: When you have a cold and eat chicken soup or drink tea to feel better, you don't believe that the chicken soup or tea actually heals the cold. You understand that you/your body heals the cold and the tea or soup simply helps. When you break a leg and get a cast you don't actually believe that the cast is what heals the bone, you do understand that you/your body heals the bone and the cast simply keeps the limb from moving to aid the body in the healing process. Under those circumstances we all actually agree that we self-heal and that tea, chicken soup and cast are aids or props. But the belief system is shaky because we still need an outside "expert" with "expert" methods to help us heal more "serious" ailments. When we take pills or resort to various treatments, we believe all of a sudden that they actually caused the healing. (Yet, when the treatment doesn't work so well, as is often the case, then we are at a loss - but we wouldn't doubt or adjust our belief system).
You may have heard of voodoo deaths, whereby someone actually ends up dying from a combination of their own fear and the combined energy of the village community that does the condemning. You may have read about the study on placebo knee surgery for arthritic patients, that ended up treating pain as well as actual surgery (!). The fact is - our beliefs are enormously powerful! And when we don't heal, it is usually because negative beliefs or residual trauma are in the way and counteract the process (there are a few exceptions, such as afflictions we are born with). When they get cleared, the body can heal itself. Check out the recent book Use Your Body to Heal Your Mind by psychologist Henry Grayson to explore this subject further.