The theory of five elements is used to interpret the relationship between the physiology and pathology of the human body and the natural environment. According to the theory, the five elements are in constant move and change, and the interdependence and mutual restraint of the five elements explain the complex connection between material objects as well as the unity between the human body and the natural world.

The order of mutual promoting among the five elements is that wood promotes fire, fire promotes earth, earth promotes metal, metal promotes water, and promotes generates wood. In this way each of the five elements has this type of mutual promoting relationship with the other, thus promoting is circular and endless.

According to the order of mutual restraining, however, wood restrains earth, metal restrains wood, etc. Each of the five elements also shares this restraining relationship with the other.