There is a link between your state of mind and your illnesses. For instance, it is said that fear affects your kidneys and anger affects your liver. Dr. Bach believed that all illnesses began with the mind and that by removing the state of mind that was causing the problem, the illness would go.
I feel that in my own experience, this would mainly apply to illnesses developed during your lifetime, and not conditions that you were born with, though there is no doubt that the remedies will help.
For me, the most important thing isn't whether I am healed or not, but rather how at peace I am feeling. Emotional angst and trauma is always far worse for me than any physical pain.