Yin and Yang are pairs of opposites: Cold-heat, high-low, thick-thin...
However, the opposition between them is not absolute, nothing is completely Yin or Yang. Everything has these two contrary natures at the same time: Yin contains the seed of Yang and vice versa. There cannot be cold without the existence of heat. If we all measured the same height, neither high nor low would exist.
This contradiction intrinsic to life is the force that moves all natural change, development, and decay.
Speaking of either of the two, as opposite poles, is referencing the other; if the shady side of the mountain is Yin, it is because there is a sunny extreme that speaks to us of the Yang part, one always exists in reference to the other. High is Yang in relation to low which is Yin, luminous is Yang only if there is something less luminous that we call Yin.
In Chinese medicine it is important because we live in relation to others: natural processes are understood in relation to others. These relationships of opposition generate constant movement and the cessation of this movement causes stress or illness.
Yin Yang Opposition in the Body
In the body the viscera are Yang in relation to the organs which are Yin, Qi is Yang in relation to Blood which is Yin, the external is Yang and the internal is Yin, the upper part of the body is Yang and the lower part is Yin. This is an example of the opposition of Yin and Yang always relative: even in the upper part of the body (Yang), it can be further subdivided into the pair of opposites, the internal (Yin within Yang) and the external (Yang within Yang). See more in: Body structures and Yin-Yang
Yin Yang Opposition in Symptoms
Everything within bodily energetics can be referenced by a pair of opposites: cold and heat, red and pale, calm and agitation, dry and wet, fast and slow, hard and soft, water and fire... are opposites to each other. For example, a pale complexion speaks to us of excess Yin while a reddish one references excess Yang. The opposition of Yin and Yang means that to know the Yin or Yang quality of a symptom, we need to observe it in relation to its opposite.
Yang Symptoms
Yang is represented by:
- Acute illnesses and rapid onset
- Pathological changes are equally rapid
- Heat is characteristic of Yang: red face, preference for cold drinks, thirst
- Restlessness and insomnia
- The illness expands or spreads in the patient
- Moves a lot, quickly
- Speaks loudly
- If sleeping, uncovers and stretches out
- See: Fullness of Yang
Yin Symptoms
Yin is represented by:
- Chronic illnesses and gradual onset
- The illness evolves slowly, the pathology persists
- Cold is characteristic of Yin: paleness, preference for hot drinks, likes to be covered
- Somnolence
- Quietness
- Soft voice
- Sleeps curled up, covered
- See: Fullness of Yin
See also: