The Yin-Yang symbol is perhaps one of the most recognizable symbols in the world. Though some people here in the West think of it as a religious symbol that is not completely accurate. It was originally a statement of how the natural world functions. The Chinese character for “yang” literally translates as “the sunny side of the hill.” Conversely, the character for “yin” translates as “the shady side of the hill.” Chinese philosophers observed that as the sun moved across the sky the shady side of the hill would gradually grow brighter and the sunny side would darken until finally the two changed places. Similarly, day gradually changes to night and the seasons change from warm to cold in a similar pattern. This state of dynamic balance was thought to govern all natural phenomenon and this way of looking at the world came to influence many areas of thought: government, art, martial arts, medicine and even interior decorating.

When applied to Chinese Medicine, the theory of Yin and Yang divides the body's functions into two main types. Functions that are active, moving and energetic and considered Yang. The intestines moving food along their length, the beating of the heart and the actions of the muscles moving the body through space are all good examples of Yang functions. Paired with these Yang functions the body also has Yin functions. Yin functions are all involved with nourishing and repairing the body. The stomach has to contract to help break down the food we eat—a Yang function—but it also has to renew its lining—a Yin function.

Yin and Yang functions are mutually dependent and support each other. If an organ's Yin functions are impaired it will eventually accumulate damage and be unable to perform its Yang function either. Take a muscle for example. If it is worked too hard with no time to rest and repair itself eventually it will be torn or strained. When that happens it cannot move at all without difficulty or pain. But Yang functions are equally important to the Yin. Think what would happen if the muscle never moved at all. It would quickly atrophy and become unhealthy. Or think how poorly your digestive system would work if it couldn't perform its Yang function of moving food through the intestines.

Both Yin and Yang functions are necessary for the body to stay healthy. Many times people recovering from an injury find it difficult to take the time and rest their body needs to heal completely. They want to get back to doing all the things they want to do and feel as though they can heal themselves through sheer effort. This is called “Fighting Fire with a Fan.” The more energy you put into waving the fan back and forth the worse the flames become. Other people become very inactive following an injury. They are afraid of causing themselves pain or perhaps injuring themselves further. Because of this they often heal from injuries weaker than before and with decreased range of motion in their joints. They are at increased risk for injuring themselves again.

In the above example, the first approach is too Yang, the second too Yin. But ignore one aspect of the body's needs to the detriment their overall health. By helping us to keep both sides of the equation in mind, Yin-Yang theory gives us a useful lens through which to examine many different aspects of our lives and plot a true course towards greater health and well-being.