Yin and Yang

Ancient Chinese people were extremely interested in their relationships and patterns which occur in nature. Rather than studying the isolated things, they looked at the world as a harmonious and holistic entity. For them, there is no single being or form could exist unless it was seen in relation to its surrounding environment. By simplifying these relationships, they tried to explain the complex phenomenon of the universe.

This theory is based on the belief that all things are composed of two basic components: Yin and Yang. This is a theory and Yin/Yang is neither materials nor energy. They combine in a symbiotic manner and comprise a method for explain relationships between objects. Yin Yang theory is a kind of logic system of thought that was applied to other areas such as medicine, material arts and the sciences. Yin Yang theory is the foundation of TCM and is used to understand complicated relationships in the body.

The Origin of the Yin Yang Theory

Our ancestors were not as distracted by our own creations and technology. They became careful observers the natural world they were so close to. Many descriptions of natural phenomenon they saw were described in animalistic terms. The original concept of Yin and Yang came from the observation of nature and the environment. It was a departure in that it described overall operating principles. It started when “Yin” originally referred to the shady side of the slope while “Yang” referred to the sunny side. Later, this observation was used in understanding other occurrences. It generally appeared that things occurred in pairs and had complementary and opposing characteristics in nature. Some examples include hot and cold, low or high, sky and earth, day and night, water and fire, active and passive, male and female and so on. Philosophers and scientists soon recognized nearly all things could have Yin and Yang properties. Yin and Yang can describe two relative aspects of the same phenomena. For example the slope mentioned earlier, or they can describe two different objects like sky and earth.

Yang is associated with energetic qualities; movement, outward and upward direction, heat, brightness, stimulation, activity and excitement.

Yin is associated with physical form of an object and has less energetic qualities; rest, inward and downward direction, cold, darkness, condensation, inhibition and nourishment.













Physiological functions






Properties of Yin and Yang

By explaining how things systematically work in relation to the universe and to each other, the Yin Yang theory creates a dynamic thought process that can be applied to everyday life.

1.     Yin and Yang opposed to each other.

Yin Yang theory states that all things have an opposing Yin and Yang aspect. There must be a dynamic balance. They are mutually controlled and inhibited by each other, which results in a continuous state equilibrium. For example, heat can disperse cold and vice versa. For TCM this example relates to the physiological functions in our body. Both the excited energy (Yang) and the inhibited energy (Yin) functions are in mutually controlled balance. If one aspect becomes excessive it suppresses the other. This will cause serious health problems because the dynamic balance is disturbed.

2.    Yin and Yang mutually create and depend on each other in order to exist.

Yin cannot exist without Yang each other nor can they stand-alone. They define each other for and can only be measured by comparing Yin to Yang. Without knowing hot there is no cold, and would only be one temperature. This is true for all units of measurement; height (Yang aspect) requires a low reference point (Yin aspect) or everything would be at one level. In addition, the comparisons between Yin and Yang are relative to the objects being compared.

The Yin Yang theory states our physical body is cannot be separated from its physiological functions. They rely on each other to achieve a balanced healthy state of being. The physical form is created and maintained by the body’s activity and the activity (Yang) of our body is nourished by its physical form (Yin).

3.     Yin and Yang change and grow in a cyclic and balanced manner.

Yin and Yang attain a balanced state by mutual control and suppression. The balance is neither static nor absolute but is maintained within certain limits. At certain times, when Yang rise then Yin decline. At other times, just the opposite. Like seasonal changes which illustrates this concept pretty well. The weather changes from cold to hot throughout winter to summer. This is a process of when Yang (hot) growth and Yin (cold) reduce. On the other hand, the weather will change from hot to cold from summer through autumn and winter. A process of when Yin growth and Yang reduce. Over time, the ratio of the hot (Yang) and cold (Yin) weather will be balanced and in harmony.

4.     Yin and Yang transform into each other.

If one energy aspect swings out of balance into an extreme, it must undergo a reverse transformation into the opposite aspect. Here are some examples of a sudden transformation

  • After summer day reaches the hottest point (extreme Yang), the weather begins changing in a reverse manner. Instead of continuing to get hotter, it starts to become cooler.
  • When winter reaches its coldest day (extreme Yin), the weather reverses its direction and becomes warmer.

This transformation is the source of all changes. This ability to changes allows both Yin and Yang to create each other. In the body, the symbiotic nature of Yin Yang transformation happens when excitatory and inhibitory functions push and pull one another.

The Application of Yin Yang Theory in Traditional Chinese Medicine

Application in human body structures

TCM concludes the human body has organic unity.  There is a sense of unity based on the opposing and complimentary relationships of Yin and Yang.  Each of the body’s organs and tissues can be classified according to Yin Yang theory based on their functions and locations.

The upper body belongs to Yang.

The lower body belongs to Yin.

Other Yin Yang pairs in the body include interior (Yin) versus exterior (Yang), the front (Yin) versus the back (Yang), the inside (Yin) versus the outside (Yang) of the limbs and the five Yin organs versus the six Yang organs.  Each organ can also be further categorized into Yin and Yang. Some examples are heart/Yin and heart/Yang and kidney/Yin and kidney/Yang.

Physiological application

Your body cannot function if it doesn’t have a physical form in which to perform in. You must also have physiological functions to consume certain physical forms (material) and metabolize, or transform, these materials to obtain energy. Your body’s physical form belongs to Yin while the body’s activities or functions belong to Yang. Because both the body’s physical forma and functions are dynamically linked, they mutually restrict and are dependent on both aspects. TCM believes health is achieved when Yin and Yang are in balance.

Pathological application

Fundamentally, TCM believes Yin Yang disharmony (unbalance) is the source for disease and physiological disorders. It is also a closed system. So, when one aspect is deficient, the other is in excess. There are many factors that cause Yin and Yang disharmony, TCM believes they are all related to the “evils” which we discussed earlier. (These evils are actually outside influences that cause disease and disrupt the flow of Qi throughout the body.) When normal Qi flows, the body functions well and have good immunity allowing easier recovery from illness.

Normal Qi is composed of both Yang Qi (physiological functions and energy) and Yin fluid (physical form and the physiological fluid of body) while the “pernicious evils” are comprised of six evils.

Wind, dryness, summer, heat and fire belong to Yang evils and conversely, cold and dampness belong to Yin evils.

Disease results from either a lack of normal Qi (deficiency of Yin fluid or Yang Qi). It can also be an excess of the “pernicious evils” is what allows the disease to either progress or transform back to a healthy state. Only by applying the Yin Yang principles to treat and diagnose disease can Yin Yang harmony can be restored and health maintained.

Diagnostic application

TCM patients are diagnosed by determining their disharmony pattern. All patterns divided into a system known as the “eight principle patterns.”

The eight principle patterns contain four pattern pairs:

1.     Interior and Exterior

2.     Cold and Heat

3.     Deficiency and Excess

4.     Yin and Yang

Among the eight patterns, Yin and Yang is the most fundamental and essential pattern pair. Yin signs aspects are associated with inhibitory, resting, passive, cold progressing internally and developing downward and worsening manifestations. Yang signs, being the opposite are associated with excitatory, active, hot, progressing externally and developing upward and improving manifestations.

The Chart of Yin Yang






Wind and cold. (i.e. common cold) generate "external influences" like an exterior pattern



An interior pattern is created by internal disharmony like a organ disorder or malfunction.



The cold pattern signs are usually related to non-excitatory physiological functions. They are manifested by the signs such as a pale face, cold limbs, aversion to cold, clear urine, or watery stools.



The heat pattern signs are usually related to excitatory physiological functions. They are manifested by signs like a red face, high fever, dislike of heat, dark urine, or constipation.



Indications of frail or weak movements, tiredness, shortness of breath, lowered voice, or dizziness indicate a deficiency pattern. Lack of energy towards normal functions is a sign.



The signs are usually related to an excess/accumulation of evils/metabolic waste. This pattern exhibits signs of heavy movements, heavy and coarse respiration, or discomfort when touched with pressure.



Yin general pattern manifestations include interior, cold and deficiency patterns.



Yang general pattern manifestations include exterior, heat and excess patterns


Body Signal

Yang signs

Yin signs


Fever, hot sense, red face, agitated and active manner

Cold feeling, pale face, low spirit, cold limbs, tired and weak


Coarse and strong voice, coarse breath, dry mouth, thirst

Low voice, lowered appetite, lack of taste in mouth, no thirst


Constipation with unusual smell, dark urine

Plentiful and clear urine


Red and scarlet tongue or yellow and black moss present on tongue

Swollen tongue material, pale appearance


Rapid and floating, flooded and strong, slippery and full pulse

Slow and sinking, weak, frail pulse