Chinese Medicine is often expressed in terms of the two complementary forces - yin and yang; and the five elements - fire, earth, metal, water, and wood. The five elements give rise to the five tastes by which all medicinal plants are evaluated. Fire gives rise to bitterness, earth to sweetness, metal to acridity, water to saltiness, and wood to sourness. Each taste is said to have a particular medicinal action; bitter-tasting herbs drain and dry; sweet herbs tonify (dampen) and may reduce pain, acrid herbs disperse; salty herbs nourish the kidneys; sour herbs nourish the yin and act as astringants, preventing unwanted loss of body fluids or Qi. Herbs that have none of these tastes are described as bland, a quality that indicates that the plant may have a diuretic effect. The taste of a plant can also indicate the organ to which it has a natural affinity.
Besides defining particular herbal tastes, the Chinese ascribe different temperatures to herbs - hot, warm, neutral, cool, and cold. Each individual herb has different properties such as taste and temperature, and enters different organs in the body. When the herbs are combined, through mutual harmony, the treatment effect is increased and the side effects reduced. A usual prescription or formula can consist of multiple herbs.
After a diagnosis is made, herbs are selected and combined, or a well- known traditional formula is prescribed. The formula is adjusted to fit the patient's symptoms and diagnosis. The formula brings about the treatment effect by regulating Qi (Energy), blood and body fluids, which are fundamental substances that form the body. This gives total harmony and balance to the whole body, helping to correct and rebalance the flow of energy and consequently relieve pain and/or restore health. When the flow of energy is blocked for any reason, there is disruption of health, resulting in pain and illness. When the energy is released and regulated, health may be restored.
