Yin Yang theory is a philosophy, which originated in ancient China. It describes the connotation of yin and yang and the changing laws of the yin and yang movement.
In ancient times, the yin yang theory was used to explain the occurrence, development, and change of things in the universe.
Ancient philosophers believed that the formation of the universe came from the material energy–Qi (Chi). The movement and change of Qi have produced bipolar “yin” and “yang”. The interaction of yin and yang gave birth to all things in the universe and promoted their development and change.
In yin and yang’s view of the universe, Qi has formed many things, such as mountains, rivers, valleys, and life. Light and darkness, fire and water, expansion and contraction are all manifestations of yin and yang.
Yin yang theory assists in the development of ancient Chinese astronomy, meteorology, chemistry, arithmetic, music, and medicine. It is the foundation of Tai Chi, Qigong, and traditional Chinese medicine.
In Chinese medicine, yin yang theory is a unique way of thinking, which explains the tissue structure, physiological functions, pathological changes, and diagnosis and treatment of diseases.
Yin yang symbol
The yin and yang symbol is also called the Tai Chi symbol and was a symbol used by ancient Chinese to record the movement of celestial bodies. It is a circle with a curve in the middle. The circle is divided into two areas of white and black by the curve. There is a small black circle on the white area and a small white circle on the black area.
The white area and black area mean opposite and their small circles of opposite colors imply mutual breeding.
Concept of yin and yang
Yin and yang is a generalization of the opposite attributes of things. In the early days, it was defined that the side where sunlight can shine belongs to yang, and the side where sunlight cannot shine belongs to yin.
With the expansion of people’s cognition, the meaning of yin and yang has been extended. Almost everything in nature can be divided into two aspects: Yin and Yang. Light, warm, spring, and summer belong to yang; dark, cold, autumn, and winter belong to yin.
The concept of yin and yang was probably formed in the Western Zhou Dynasty. Both <I Ching> and <Classic of Poetry> have recorded about yin and yang. People use yin and yang to explain the changes of complex things that are difficult to observe.
According to <Guoyu>, there was an earthquake in Shaanxi Province in 780 AD. Scholars at that time believed that the earthquake was caused by the inconsistency of the two material movements of Yin and Yang inside the earth.
During the Spring and Autumn and the Warring States Periods (770 BC-221 BC), China had developed a hundred schools of thought, such as Taoism, Legalism, Confucianism, and Mohism.
At that time, the philosophical theory also entered a period of rapid development, and yin yang theory gradually formed. Philosophers believed that there were two opposing forces of yin and yang inside things and these two forces were moving and interacting. They believed that the change of the seasons and the change of day and night are the results of the movement and interaction of yin and yang.
The existence, movement, and change of yin and yang are the basic laws of the universe. The author of <Huangdi Neijing> explains many problems in traditional Chinese medicine and the relationship between humans and nature by using the yin yang theory.
Yin and yang attributes of things
Opposing things or the two opposing aspects of a thing can be summarized by the attributes of yin and yang. Examples of opposing things are sky and earth, sun and moon, water and fire, etc; the two opposing aspects of a thing are hot and cold, rise and fall, bright and dark, etc.
Take water and fire as an example. The property of water is cold and the property of fire is hot. Water belongs to yin and fire belongs to yang.
Take the movement of matter as an example. Water vaporizes into water vapor and water solidifies into ice. Gas belongs to yang, solid belongs to yin, and liquid belongs to the relative balance of yin and yang.
Generally, many words such as “positive”, “strong”, “outgoing”, “rising”, “bright”, etc. belong to yang. And some words such as “negative”, “soft”, “falling”, “cold”, “dark”, etc. belong to yin.
|Space（Orientation）||up, left, south, outward||down, right, north, inward|
|Temperature||warm, hot||cold, cool|
|season||spring, summer||autumn, winter|
|State of Motion||gaseous, rising, movement, excitement, hyperfunction||solid-state, lowing, motionless, inhibition, recession|
The yin and yang attributes of things are the comparison of the functional attributes of things and the state attributes of things. Yin and yang attributes are absolute and relative.
The internal properties of a thing remain unchanged, and its internal yin and yang properties will not change. For example, the boiled water contrasts with fire. Both of them have a high temperature, but boiled water is still water and its internal property belongs to yin.
When all attributes of a thing change, its yin and yang attributes also change.
Relativity of yin and yang attributes
Mutual transformation of yin and yang
Under certain conditions, yin and yang can transform each other. Yin can be transformed into yang and vice versa. For example, the circulation of water in nature is the transformation of yin and yang.
Yin and yang contained in each other
Either side of yin and yang can divide into yin and yang. For example, water belongs to yin, but the external property of hot water belongs to yang. Hot water contrasting with water implies that yin contains yang and vice versa.
After one of the yin and yang is divided into yin and yang, it can be further divided into yin and yang. The opposition of things has always existed in nature.
Different comparative things
The attributes of yin and yang are divided by comparison. When the compared things change, their yin and yang attributes will also change.
When spring contrasts with winter, spring is warm and belongs to yang and winter is cold and belongs to yin. When spring contrasts with summer, summer is hot and belongs to yang and spring is cool and belongs to yin.
Interaction of yin and yang
This relationship refers to the mutual struggle, mutual restraint, and mutual exclusion of yin and yang among unified individuals. The mutual restraints between yin and yang maintain the dynamic balance between yin and yang and promote the occurrence, development, and change of things.
The changes of the seasons are more obvious. The rise of yang causes the summer heat and the rise of yin causes the winter cold. The climate cycle is the result of the mutual restraints of yin and yang in nature.
Yin and yang in the human body also remain a dynamic balance. The Yang (Qi) in the human body promotes the body’s life activities and metabolism. The yin (vital essence) in the human body inhibits the body’s life activities and metabolism.
The balance between yin and yang maintains the health of the human body. If this dynamic balance is disrupted, it represents the emergence of disease.
Interdependence and mutual promotion
Neither yin nor yang can exist separately from the other. Each of them has the existence of the other as the condition for their own existence. “Up” and “down” belong to orientation. “Up” is yang and “down” is yin. Without “up”, “down” would not exist.
Yin and yang can promote each other. Sleeping at night is to have enough power during the day. During the day, humans show excitement and vitality. At night, humans show inhibition and exhaustion. Yin promotes yang and yang promotes yin.
Growth and consumption
In the process of mutual restriction between yin and yang, one side will increase while the other side will decrease, and vice versa.
The climate gradually changes from cold to warm, which represents the decrease of yin and the increase of yang. The climate gradually changes from hot to cold, which represents the decrease of yang and the increase of yin.
In the process of interdependence and mutual promotion between yin and yang, one side will increase while the other side will increase, and vice versa. Rainfall is higher in spring and summer, and less in autumn and winter.
Yin and yang can automatically coordinate and maintain the dynamic balance between them. The self-healing of some diseases is the result of the automatic coordination of yin and yang.
The mutual transformation and the mutual inclusion of yin and yang are also the interaction of yin and yang.
Application of yin yang theory in Traditional Chinese Medicine
Explain the organization of the human body
The human body is a single whole. The surface of the body is yang and the inside is yin. The upper body of the body is yang, and the lower body is yin. The back is yang and the abdomen is yin. The back of the hand is yang and the palm of the hand is yin.
According to the position of the five internal organs, the heart and lungs are in the upper part; the spleen, liver, and kidney are in the lower part. Heart and lung belong to yang; spleen, liver, and kidney belong to yin.
In Five Elements Theory, the heart belongs to fire, the lung belongs to metal, the spleen belongs to earth, the liver belongs to wood, and the kidney belongs to water. The fire belongs to yang, the metal belongs to yin, the earth belongs to yin, the wood belongs to yang, and the water belongs to yin. the lung implies that yang contains yin and the wood implies that yin contains yang.
One of the five internal organs can also contain yin and yang, such as kidney yin and kidney yang. The above division of yin and yang is a dichotomy of yin and yang.
The yin and yang division of the twelve meridians is a trisection. Yin is divided into Taiyin, Shaoyin, and Jueyin, and yang is divided into Yangming, Taiyang, and Shaoyang.
For example, hand Taiyin lung channel, hand Jueyin Pericardium Channel, hand Shaoyin heart channel, hand Yangming large intestine channel, hand Shaoyang Sanjiao channel, hand Taiyang small intestine channel, foot Taiyin spleen channel, foot Jueyin liver channel, foot Shaoyin kidney channel, Foot Yangming stomach channel, foot Shaoyang gallbladder channel, foot Taiyang bladder channel.
The trisection method of yin and yang is mainly used to explain the law of climate change, the yin and yang attributes of meridians and viscera, and the dialectical system of six meridians of typhoid.
Explain the physiological functions of the human body
The normal work of organs is a necessary condition to maintain life activities. The coordination between organs is the result of the mutual restriction and promotion of yin and yang.
Organs (five zang-organs) that store nutrients belong to yin, and organs (six fu-organs) that consume nutrients belong to yang. Consumption of nutrients (essence) can produce energy (qi), which transforms yin into yang. Consumption of energy (qi) can obtain nutrients (essence), which transforms yang into yin.
The mutual restriction, promotion, and transformation of yin and Yang maintain the balance. Only under this balance can life activities and physiological functions be carried out orderly.
Explain pathological changes
The invasion of pathogenic factors into the human body will lead to the imbalance of yin and yang, resulting in diseases.
Traditional Chinese medicine divides the etiology into six climatic evils. In the six climatic evils, wind-evil, pathogenic summer-heat and pathogenic fire (heat evil) belong to yang and cold pathogen and damp evil belong to yin.
The occurrence and development of the disease is a process of the struggle of evil and justice. When yang evil invades the body, yin will resist, and vice versa. When yang wins, people will show symptoms such as fever, irritability, and facial redness. When yin wins, people will show symptoms such as cold, cold pain, and diarrhea.
When the mutual restriction between yin and yang is destroyed, one of them will be stronger than the other. Yang deficiency is yin sthenia, and people will appear pale and feel cold and tired. Yin deficiency is yang hyperactivity, and people will have a fever, night sweats, and dry mouth.
When yang deficiency reaches a certain level, the yang cannot be converted into yin, which will cause yin deficiency and vice versa. Qi deficiency caused by the deficiency of essence belongs to yang deficiency caused by yin deficiency. Blood deficiency caused by qi deficiency belongs to yin deficiency caused by yang deficiency.
Diagnosis and treatment of diseases
Chinese medicines determine the disease by observation, listening, smelling, questioning, pulse feeling and palpation.
The diseases characterized by bright colors belong to yang, and vice versa. The diseases characterized by weak breath belong to yin, and vice versa. Surface symptoms and heat syndromes belong to yang. Internal disease and cold disease belong to yin.
The yin yang theory is used to analyze intricate and various diseases. After knowing the yin and yang of the disease, Traditional Chinese medicine doctors use Chinese herbs, acupuncture, and other methods to regulate the yin and yang in the body.
Heat symptom complex needs to be treated with Chinese herbal medicine with cold properties. Symptoms caused by cold factors need to be treated with Chinese herbal medicine with warm properties.
When the yang is strong and the yin is weak, the consumption of yang is used to treat diseases and vice versa. When Yin deficiency and yang hyperactivity in the body, they should supplement yin and suppress yang, and vice versa. When Yin deficiency caused by yang deficiency, it should mainly supplement yin and moderately supplement yang, and vice versa.
Chinese herbal medicine properties
The yin yang theory summarizes the properties of Chinese herbal medicine, which is the basis of the clinical use of traditional Chinese medicine. The properties of Chinese herbal medicine has Four Qi, Five tastes, and lift ups and downs.
Four Qi refers to the four medicinal properties of Chinese herbal medicine, which are divided into cold, hot, warm and cool. Cool and cold belong to yin, and warm and hot belongs to yang.
Most of Chinese herbal medicines properties with cold or cool can clear away heat and relieve fire. Most of Chinese herbal medicines properties with warm or hot can dispel cold and warm interior.
Five flavors refer to five tastes of Chinese herbal medicine, which are sour, bitter, sweet, spicy and salty. Some Chinese herbal medicines have light or astringent taste. Sour, bitter, salty and astringent belong to yin, and spicy, sweet, and light belong to yang.
Lift ups and downs refer to the tendency of Chinese herbal medicine, which includes rising, falling, floating, and sinking.
Rising and floating belong to yang. This kind of Chinese herbs has the function of divergence and refreshing. Falling and sinking belong to yin. This kind of Chinese herbs has astringent and laxative functions.
In the process of clinical medication, both the cause of disease and the properties of Chinese herbal medicines need to be considered. Traditional Chinese medicine formula is not a simple drug matching.