Five thousand years ago Chinese physicians developed an approach to healing that we now know as the Five Element Theory. The Chinese believe that the Five Elements - Wood, Fire, Earth, Metal, and Water - govern the physical, emotional, and spiritual existence of people just as they regulate the growth and change cycles in the external world. An excess or deficiency in any of these basic forces affects your physical health and emotional well-being.
Each of the Elements has its own unique characteristics, which we can see in ourselves in varying degrees. For instance, Wood, which has the ability to grow through rocks if necessary, is determined and rooted. If it is too determined, it can become hard or stubborn. Like a dead sapling that grew through a large rock only to find that there were not enough nutrients there to support it. Or like a workaholic who is so determined to get to a higher rank in his company that he loses sleep, his health, his wife, and his perspective on life altogether.
All of the Elements are tied to certain organs of the body, i.e. Wood is connected to the Liver and the Gall Bladder (Chinese organs are not finite like Western organs. They are systems that run through the entire body.) That means that whatever Element(s) we most embody, the associated organs are usually affected in us when there is an imbalance in the system. Such as the example of the Wood man above - perhaps his liver would have a deficiency and he'd end up with sleep disturbances, chronic tension in his neck, etc.
With the Five Element Theory, there is a more systematic approach to healing and less of a guessing game about what to do for a given person. It is just a matter of re-centering their Elemental imbalances.