Yin and Yang
Yin and Yang are fundamental concepts that provide a model of harmony and balance in the Universe, and can also be applied to the study of health and illness in the human body.
In TCM acupuncture, human health relies on the balance of Yin and Yang and it is when an imbalance of Yin or Yang (or both Yin and Yang) occurs that we develop illnesses.
The Chinese character of Yin originally referred to the shady side of the mountain, whilst the character for Yang referred to the sunny side of the mountain. From this, further concepts of Yin and Yang can be developed.
The Yin and Yang image has now become iconic, and is often used to represent balance, harmony etc. and yet within this simple illustration lies the depth and breadth of TCM.
Yin and Yang are seen to flow in a constant cycle of harmony, each balancing the other, with neither Yin nor Yang being excessive or deficient.
Yin is seen representing being still, coolness, contraction, night time, heaviness etc. whilst Yang represents movement, warmth, expansion, day time, lightness etc.
Basic Clinical Principles
The root cause and development of disease no matter how complex can be simplified in terms of an imbalance between Yin and Yang and a correct diagnosis reached. As ancient Chinese medical texts state, the essential technique of needling consists of striking a balance between Yin and Yang.
Yin and Yang theory is not only applied clinically in the context of diagnosis and principles of treatment but also in the selection of points and the technique of needling used.
For example, certain acupuncture points may be selected to nourish Yin where there is a Yin deficiency and subdue or reduce Yang where there is a Yang excess.
The basic principle in any acupuncture treatment is therefore to adjust the relative levels of Yin and Yang and restore balance between them.
Properties of Yin and Yang
There are five main properties of Yin and Yang:
- Yin and Yang are two aspects of a whole – Yin and Yang aspects are in everything: day and night, male and female, hot and cold, being active and being relaxed.
- Yin and Yang are divisible – for example, a 24-hour day can be divided into day time (Yang) and night time (Yin).
- Day time (Yang) can be divided into Sunny (Yang) and Cloudy (Yin), Sunny could then be divided into direct sunlight (Yang) and indirect sunlight (Yin) and so on.
- Yin and Yang are interdependent – neither Yin nor Yang can exist in isolation and only have meaning in relation to the other e.g. there is no hot without cold, light without darkness, male without female etc.
- Yin and Yang control each other – Yin and Yang mutually balance each other: as Yang rises, Yin decreases and vice versa.
- Yin and Yang transform into each other – at the point of maximum Yang, Yin will start to rise and vice versa, and Cold (Yin) can transform into Heat (Yang).
Basic Imbalances of Yin and Yang as Applied to Our Health
The illustration below, adapted from The Foundations of Chinese Medicine, shows how we can apply the idea of Yin and Yang to develop a TCM model of human health.
If we look at the top illustration, at birth we have a balance of Yin and Yang where our health is just right – we’re not too hot or too cold, we have enough strength and energy to do our activities but are not overactive and can rest in the evening etc.
In TCM clinical practice, we assume that an imbalance of Yin, Yang or both has occurred and is manifesting in one of these four ways: a deficiency of Yin, a deficiency of Yang, an excess of Yang, a mixed condition of a deficiency of Yin and an excess of Yang.
Some of these concepts become clearer by looking at the Zang-Fu organ system and the patterns of disharmony arise and manifest in them.
Yin Deficiency
In this first situation at the bottom left, we can see that the Yin energy has decreased and this have resulted in a relative excess of Yang. In this case, we would be looking to nourish Yin to try and re-balance Yin and Yang.
Yang Deficiency
In the second situation, we can see that the Yang energy has decreased and this have resulted in a relative excess of Yin. In this case, we would be looking to tonify Yang to try and re-balance Yin and Yang.
Yang Excess
In the third situation, we can see that Yang has become excessive and resulted in an absolute Yang excess. In this case, we would be looking to reduce Yang to try and re-balance Yin and Yang.
Mixed Deficiency and Excess
In the fourth situation, we can see that Yin has become deficient and Yang has become excessive. In this case, we would be looking to nourish Yin and reduce Yang in order to try and re-balance Yin and Yang.
