People often say, “Yin and Yang must be balanced.” So, what is Yin, what is Yang, and what exactly is Yin-Yang?From the perspective of Chinese character formation, there are pictographs, associative compounds, phonetic compounds, indicative characters, borrowed characters, and transferred annotations. However, to understand what Yin and Yang are, one must first know the origins of the characters “Yin” and “Yang.” Etymologically, both “Yin” and “Yang” contain the left radical “阝,” which is the ancient character for “阜.” According to the “Shuowen Jiezi,” “阜 means a large landmass, a hill without stones, represented pictographically,” indicating a type of earthen hill without stones. Thus, both “Yin” and “Yang” are metaphorical descriptions of this stone-free hill, “阜.” Initially, “Yang” referred to the sunlit side of the hill, while “Yin” referred to the side not illuminated by sunlight. This reflects a more primitive meaning of Yin and Yang, which changes over time, leading to a sublimation and extension of the concept.
In the “Suwen: On the Separation and Combination of Yin and Yang,” it states: “Qibo said, ‘The external is Yang, the internal is Yin. Therefore, the middle is Yin…'” Here, Yin and Yang acquire a stable definition. It is evident that the original meaning of Yin and Yang is very simple, representing the orientation of sunlight. Facing the sun is Yang, while turning away from it is Yin. In the process of understanding, Yin and Yang enter a stage of sublimation, extending to the cold and warmth of the climate, the directions of up and down, left and right, inside and outside, and the states of movement and stillness. Generally speaking, anything that is moving, outward, rising, warm, and bright belongs to Yang; conversely, anything that is relatively still, inward, descending, cold, and dark belongs to Yin. In terms of heaven and earth, light weather is Yang, while heavy and turbid earth energy is Yin; regarding water and fire, water is cold and moist, thus belongs to Yin, while fire is hot and rises, thus belongs to Yang.
The “Huangdi Neijing” begins with “The First Question of the Yellow Emperor,” where a path to health emerges through the dialogue between the Yellow Emperor and Qibo, stating, “Follow Yin and Yang, harmonize with the techniques and numbers.” So, how do modern people view such a statement? I believe most people do not find enlightenment or relief in Qibo’s answers; rather, they seek external reasons. For instance, people today face immense pressure regarding housing, cars, and finances, and under such stress, life can feel like a knife, hastening aging. Is this truly the case? Without delving into sociological comparisons of various societal pressures, let us directly explore the mysteries of human health by gradually peeling away the layers of the “following Yin and Yang, harmonizing with techniques and numbers” path to health.
Every aspect of disease and every detail of life manifests as a set of opposing yet unified phenomena. The expressions of exterior and interior, cold and heat, deficiency and excess in the process of disease are just as evident in the comings and goings of people in the world. A newborn arrives crying, yet when a person departs, they often do so peacefully; entering the world, they come with their thumb tucked in a fist, while leaving, they are often referred to as having “let go of the world.” Consider this life and death, crying and laughing, clenching a fist and letting go, all of which are expressions of opposing phenomena. In this regard, like the coding of computer information, Traditional Chinese Medicine (TCM) does not use “0” and “1” to represent these concepts but rather uses Yin and Yang to summarize them. As a form of ancient Chinese materialism and dialectical thought, it posits that the world is material, and the material world is nurtured, developed, and changed under the influence of Yin and Yang energy. From the perspective of the opposing meanings of each pair, exterior symptoms, heat symptoms, and excess symptoms can be categorized as Yang symptoms; while interior symptoms, cold symptoms, and deficiency symptoms can be categorized as Yin symptoms. Therefore, Yin and Yang serve as the overarching principle in the Eight Principles, where all diseases can be classified under the grand principles of Yin or Yang.
All things have two sides, and these two sides can be summarized and unified by Yin and Yang, but the division between them does not have strict boundaries. The world is material, yet material is also in a state of movement and change, so Yin and Yang are not isolated and static; rather, they exist in a relationship of relativity, dependence, growth and decline, and transformation. To have a comprehensive understanding of the changes in Yin and Yang, let us briefly outline a few points:
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Yin and Yang are mutually rooted and sourced.
TCM states, “Yang is rooted in Yin, and Yin is rooted in Yang,” “Lonely Yin does not give birth, and solitary Yang does not grow,” and “Without Yang, Yin cannot be born; without Yin, Yang cannot transform.” This means that Yin and Yang are interdependent, similar to dialectical philosophy, where they develop through mutual struggle and exist through mutual opposition; that is, neither the Yang side nor the Yin side can exist independently without the other.
“The Yellow Emperor said: Since ancient times, those who communicate with heaven are the root of life, based on Yin and Yang. Between heaven and earth, within the six harmonies, its energy spans the nine regions, nine orifices, five organs, and twelve meridians, all connected to the weather. Its life is five, its energy is three; those who violate this will be harmed by evil energy, which is the root of longevity.” From the Yellow Emperor’s words, we can easily understand that the close connection between humans and the natural world has been the foundation of life since ancient times, and Yin and Yang are the foundation of life. In the natural world, the external is Yang, the internal is Yin; above is Yang, below is Yin; daytime is Yang, nighttime is Yin. In terms of human physiology, functional activities belong to Yang, while nutritional substances belong to Yin. “Lonely Yang does not give birth, solitary Yin does not grow” indicates that the two are mutually dependent, living and dying together. Nutritional substances are the material basis for functional activities, but they also require functional activities for absorption.
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Yin and Yang are in a state of mutual growth and decline.
“Yin and Yang interpenetrate, like a ring without end,” meaning that Yin and Yang each have their “meeting points,” where they exit and re-enter, entering extremes and returning, circulating internally and externally, life continues endlessly, indicating that both sides of Yin and Yang move and change like a pendulum based on their opposing roots. Nevertheless, there remains a question of Yin and Yang balance, akin to the pendulum of a clock; if the left and right, or up and down movements are roughly equal, the clock can accurately tell time. Otherwise, a disorder occurs, and the clock cannot correctly inform people of the time, just as when people exceed certain limits of “Yin and Yang growth and decline,” they cannot maintain relative balance, leading to an excess or deficiency of one aspect of Yin or Yang, resulting in disease.
On the other hand, people also utilize this theory to grasp the manifestations of health in the body. Clinically, the growth and decline of Yin and Yang are used to explain different clinical symptoms. For example, symptoms such as stomach cold pain and diarrhea after exposure to cold belong to Yin excess, thus presenting cold symptoms; while acute pneumonia, characterized by high fever, thirst, and red skin, belongs to Yang excess. Of course, it is not always a matter of left or right representing the excess or deficiency of Yin and Yang; sometimes it is due to deficiency. Deficiency is Yin, while excess is Yang; here, deficiency and excess are relative. Both deficiency cold and deficiency heat belong to this situation. If a certain organ’s Yang is relatively deficient, this is Yang deficiency, at which point “Yin” is relatively prominent, as cold belongs to Yin, thus Yang deficiency presents cold symptoms, a phenomenon termed “deficiency cold.” Conversely, if a certain organ’s Yin is relatively deficient, this is Yin deficiency, at which point “Yang” is relatively prominent, as heat belongs to Yang, thus Yin deficiency presents heat symptoms, a phenomenon termed “deficiency heat.”
Of course, one can also infer bodily issues based on the rules of Yin and Yang growth and decline, and symptoms can also reflect the interrelationship of Yin and Yang growth and decline. On one hand, this can serve as a diagnostic tool; on the other hand, it can facilitate a process of mutual verification from symptoms to fundamental pathology. Specifically, the relationship between the growth and decline of Yin and Yang and bodily symptoms can be summarized as follows: first, Yin symptoms primarily manifest as a dull complexion, lethargy, cold limbs, shortness of breath, lack of desire to speak, no thirst, clear urine, loose stools, pale tongue, and weak, thin pulse; second, Yang symptoms primarily manifest as a flushed face, body heat, irritability, loud voice, thirst with a desire to drink, dark urine, dry stools, yellow tongue, and rapid, strong pulse.
From the relationship of Yin and Yang growth and decline, we can easily find answers to everyday phenomena, such as why sometimes we feel cold when sweating, or why we can lose weight drastically after just two days of diarrhea. The reason lies in the internal Yin, thus their movement direction is consistently outward. When “Yin prevails, it is cold;” excessive sweating leads to cooling, which can result in deficiency! Therefore, from a health perspective, a normal person following the “Yang path” often leads to “excess” and illness; while a weak person following the “Yang path” can actually strengthen, resulting in health. Thus, “Yang path excess” is merely a principle. Ignorance can lead to illness; understanding and utilizing it can effectively prevent disease. Therefore, as a path to health, or a technique for health preservation, whether it is good or bad depends entirely on the user.
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The relativity of Yin and Yang.
Yin and Yang are two attributes that explain things, representing two opposing yet unified aspects, summarizing the interrelationships of all things in the world. Moreover, the term “relative” here does not refer to the same reference point but rather to different reference points. In other words, it must be determined based on comparatives. In terms of the human body, the surface is Yang, while the internal organs are Yin; but regarding the internal organs, the six fu organs are Yang, while the five zang organs are Yin; and further, among the five zang organs, the heart and lungs above are Yang, while the liver and kidneys below are Yin; regarding the kidneys, the essence stored in the kidneys is Yin, while the “mingmen fire” of the kidneys is Yang. Thus, it is evident that the Yin and Yang attributes of things are relative, and Yin and Yang are discussed in a comparative context.
The relativity of Yin and Yang also lies in the fact that under certain conditions, the attributes of Yin and Yang can transform into one another; Yin can turn into Yang, and Yang can turn into Yin. If the “relativity of Yin and Yang” is merely a summary of attributes, then transformation is a process from quantitative change to qualitative change. The “Suwen” states, “Heavy Yin must lead to Yang, heavy Yang must lead to Yin,” and “Extreme cold produces heat, extreme heat produces cold,” which ultimately means that extremes must reverse. When cold reaches its extreme, it may transform into heat; when heat reaches its extreme, it may transform into cold. This is also why people often find that especially children, during high fevers, suddenly exhibit signs of cold extremities, weak pulse, and impending crisis. Additionally, various clinical symptoms that transition from excess to deficiency, from deficiency to excess, from exterior to interior, and from interior to exterior are also examples of Yin and Yang transformation.
In summary, adhering to the natural way of heaven, striving for the “relative balance” of Yin and Yang, is a significant characteristic of Chinese-style health preservation and a key principle of health preservation. As stated in the “Suwen: On the Correspondence of Yin and Yang,” “Yin and Yang are the way of heaven and earth, the framework of all things, the parents of change, and the root of life and death.” Only by recognizing the movement laws of the opposition and unity of Yin and Yang can the path of health preservation become broader and broader. [The images in this article are sourced from the internet; if there is any infringement, please contact us for removal]