Yin Yang are the two the most fundamental concepts of East Asian culture and pervade extensively the entire corpus of Chinese Medicine. Although there are several different ways of interpreting them, their Chinese characters are generally described as portraying the sunny (yang) side and and the shady (yin) side of an hill.
陰 | 陽
They can be seen as archetypes of anything that expands/initiates (yang) and contracts/receives (yin) in our perceivable universe: two opposites which complement each other interacting continuously in the attempt to go back to an indistinguishable unity. For this reason they can also describe:
- Male / Female
- Sun / Moon
- Day / Night
and from a medical point of view
- Inside of the body / Outside of the body
- the solid organs and the empty bowels
basically anything and its correlative counterpart.
All the Chinese Medical classics insist repetitively on the fact that Chinese Medicine is based on the theories of the Five Elements and Yin/Yang.
“Yin Qi and Yang Qi may be plenty or scanty,
which is why there are three Yin and three Yang”
Therefore, when referring to the Yin and Yang theory the Chinese sages were actually talking about the three Yin and Yang describing the channel system, the divisions of the body, the progression of any disease from the outside to the inside.