Chinese herbology is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). An editorial in Nature stated that TCM is largely pseudoscience, with no valid mechanism of action for the majority of its treatments.
The term herbology is misleading in the sense that, while plant elements are by far the most commonly used substances, animal, human, and mineral products are also utilized. Thus, the term "medicinal" (instead of herb) is usually preferred as a translation for 藥 (pinyin: yào). The effectiveness of traditional Chinese herbal therapy remains poorly documented. There are concerns over a number of potentially toxic Chinese herbs.
Four Natures
The Four Natures are hot, warm, cool, cold or neutral, in terms of temperature. Hot and warm herbs are used to treat cold diseases, while cool and cold herbs are used to treat heat diseases.
Five Flavors
The Five Phases, which correspond to the Five Flavors.
Substances may also have more than one flavor, or none. Each of the Five Flavors corresponds to one of the zàng organs, which in turn corresponds to one of the Five Phases. A flavor implies certain properties and therapeutic actions of a substance. Saltiness is drains downward and softens hard masses. Sweetness is supplementing, harmonizing, and moistening. Pungent substances are thought to induce sweat and act on qi and blood. Sourness tends to be astringent in nature. Bitterness is drains heat, purges the bowels, and eliminates dampness.