Based on observation of the natural world, ancient Chinese acknowledges the patterns of transformation and change in the universe. The Five Element theory was expanded from the Yin-Yang theory and explores a more complex relationship between objects. The theory contains five basic elements: Wood, Fire, Earth, Metal, and Water; each substance has its own specific characteristics and properties that represent all articles in the universe.
Traditional Chinese Medicine practitioners relate the natures to our human body. The Five Element theory has become one of the most important thoughts in traditional Chinese medicine; this method is applied to diagnose problems and is used in acupuncture treatment. In TCM, the Five Elements theory is used to interpret the relationship between the physiology and pathology of the human body with the natural environment. Understanding the relationships of the five elements is the first step to achieving a harmonious balance between nature and life.
Human body function has a close correlation to nature. The five elements of wood, fire, earth, metal, and water are not isolated; rather they work closely together and have their own internal orders and patterns. There are two rules that govern the five elements: the mutual generation cycle and the mutual restriction cycle. The mutual generation cycle refers to the manner in which the elements create one another. For example, wood easily burns and makes a fire. The fire produces ash that creates the earth. The earth contains minerals where metal can be mined; when metal is heated and cooled, water droplets are found over it. Water promotes the growth of trees and completes the cycle. On the other hand, mutual restriction cycle refers to the manner in which the elements restrict and control one another. For example, wood can break up the soil and deplete the earth's nutrients, thus controlling the earth. Earth contains water in many places, but the soil prevents flooding, which controls water. Water puts out fire and controls its spread. Fire controls metal by the ability to melt it. This controlling process offsets the generating power, preventing one form from overacting its function.
The relationship between the five elements plays an important role in maintaining a balanced and healthy body.
This table shows the relationship between the five elements, nature and the human body.
| Wood | Fire | Earth | Metal | Water | |
| Season | Spring | Summer | Late Summer | Autumn | Winter |
| Orientation | East | South | Middle | West | North |
| Color | Green / Blue | Red | Yellow | White | Black |
| Organ | Liver /
Gall Bladder |
Heart /
Small Intestine |
Spleen / Stomach | Lung /
Large Intestine |
Kidney /
Bladder |
| Taste | Sour | Bitter | Sweet | Pungent | Salty |
| Emotions | Anger | Joy | Thought | Grief | Fear |
| Voice | Shout | Laugh | Sing | Cry | Groan |