Five Element Theory

The 5 element theory describes the stages of a naturalistic basic cycle. The 5 stages of this cycle are Water, Wood, Fire, Earth and Metal. Each of these elements has an effect on the others in the process of the cycle.
Water
The first element in the cycle is Water, representing the most extreme Yin state. It is the phase when the energy is stored, awaiting a time to explode outward, initiating a new life cycle. Winter is the season associated with Water. If the energy of water can be retained, it will provide strength through the life cycle. If the energy is wanted, the remainder of the cycle will be weakened.
Deficiency of water manifests in fear, paranoia, poor resistance, cold, lower back and knee pain and general bodily weakness.
Wood
Wood represents the next phase of the cycle. In this phase, the concentrated energy deveoped in the Water phase explodes outward, starting a new period of activity. Spring is the season for the Wood phase. Wood energy rises and expands, resulting in what some experience as "spring fever". Wood is New Yang. This is a time of creation and growth.
When the Wood energy is repressed, one can experience irritation, anger, hatred and rage. When the Wood energy is depleted, there may be lethargy and depression.
Fire
The next phase of the cycle is the Fire phase. Fire represents Full Yang, or the energetic phase of the cycle. Summer is the corresponding season. This is the most expansive time of the year. Activity is at a peak, and contentment and cooperation prevail.
When the Fire energy is blocked, it is expressed at heat or tension, especially in the neck, shoulders and head. When Fire energy is deficient, one may be suspicious, paranoid, lose the memory, or experience emotional unrest.
Metal
Fire is followed by Metal, which is representative of the Fall season. This stage begins the withdrawal process, where the energy of the Fire stage can be processed and readied for harvest. This is a time to get of excess turbid energy before the lean phase of winter begins. Metal represents a time of inner reflection and meditation, when one can draw in and store the essential energies that are useful.
Blockage of the Metal element may result in melancholy and grief. Physical manifestations can include chest pressure, breathing difficulties and low resistance to colds and flu. Excess can result in continuous sobbing and draining of the body's essential energies.
Earth
The final phase is represented by the Earth element. The Earth is the centering and balancing element in the cycle. Thus the Earth element is always present, even in the other phases of the cycles. It acts as a non-judgemental influence, providing understanding, contemplation and a mature energy.
If the Earth influence is excessive, one worries too much, losing the overall perspective, resulting in hypochondria, digestive and blood disorders and menstrual disorders in women. When the energy is deficient, the mind becomes sluggish, resulting in depression and fatigue.
The Creation Cycle:
Water creates Wood.
Wood creates Fire.
Fire generates Earth.
Earth generates Metal.
Metal creates Water.
The Control Cycle:
Water controls Fire.
Fire controls Metal.
Metal controls Wood.
Wood controls Earth.
Earth controls Water.
The Creation and Control cycles interact constantly to maintain an overall balance in the system. The five elemental energies play a vital role in the Chinese herbal system. Each of the herbs contains one or more elemental energies, and are categorized according to the type of elemental energy that is predominant in the herb and how it influences the human energy system.