The theory of TCM is rooted in the continuous summary of medical experience and the Five-element Theory of ancient China, which believes that man and nature are one unity, namely, “harmony between nature and man” or “correspondence between nature and man”. According to the TCM theory, there exist close connections between the law of human activities such as getting ill and the natural changes, like seasons, climates, regions, locations and different times in a day. For this reason, TCM doctors adjust their treatment methods to the same kind of disease according to different seasons. regions and individuals, instead of taking uniform treatment or only dealing with the nidus.
Theory of Yin and Yang
According to the Shuowen Jiezi( Explaining Simple and Analyzing Compound Characters), “Yin” means “darkness, i.e. the northern slope of a mountain and the southern bank of a river”. Another book Shuowen Xizhuan explained“Yin” as“ the northern slope of a mountain and the southern bank of a river where sunlight cannot reach”. The sunward side is called ” Yang” while the dark side is called Yin”. It was the original recognition the ancient Chinese people had about the Yin and Yang theory, though superficial and raw.
It was thought by the ancient Chinese people that human was a component of nature and was made up of two major matters: yin and yang. Yin refers to the rotating and cohesive vapor and yang the diffuse vapor. These two kinds of vapor are a unit of opposites, and keep changing and moving all the time. In the mind of the ancient Chinese people, everything that was fierce, moving, exocentric, uprising, warm or bright was in the scope of yang: everything that was relatively still, conservative, descending, cold or gloomy was in the scope of yin. Yin and Yang are interdependent and opposite, and one can transform into the other under certain conditions. It was a kind of abstract understanding the ancient Chinese people had about the universe’s antinomy regulations and a kind of category of philosophy about the universal unit of opposites as well as the laws of thought.
Being applied to TCM as a philosophical concept, the Theory of Yin and Yang can be seen everywhere in both the theories and practice of TCM.
From the perspective of human body morphology, the upper part of the body is called yang and the lower part yin; the surface is called yang and the internal yin; back is called yang and belly yin; the lateral side of limbs is called yang and the medial side of limbs yin; the five Zang-viscera storing energy qi are called yin and six fu organs and the triple burner channel, transmitting qi, is called yang.
TCM considers the healthy state of the human body as a balance between yin and yang. Once the dynamic balance was interrupted, people get sick. For example, a man with too much yang-qi tends to suffer from fever. thirst and sweating, and his body fluid of the yin organs is likely to be damaged; a man with too much yin-qi is more likely to feel cold and bear diarrhea. TCM helps people recover to the healthy balance state by correcting the disorder with medicines, acupuncture or moxibustion according to each person’s specific symptoms.