Inheriting the legacy of Qi and Huang, a public account with substance and warmth
The Concept of Body FluidsBody fluids (jinye) refer to all normal fluids in the body and are the fundamental substances that constitute and maintain life activities. In contrast to Qi, body fluids are considered Yin in nature, hence they are also referred to as “Yin Jin” or “Yin Ye”. The scope of body fluids is broad, primarily referring to the liquids and their metabolites within the organs and tissues, including secretions such as mucus, tears, and saliva, as well as excretions like sweat and urine. Body fluids are distributed throughout the body; within the vessels, they can become components of blood, while outside the vessels, they permeate the organs and interstitial spaces.
Body fluids are a collective term for Jin and Ye, which have certain differences in properties, distribution, and functions. Physiologically, Jin is relatively thin and flows easily, primarily distributed in the skin, muscles, and orifices, playing a moisturizing role and can infiltrate the blood vessels to generate blood. Ye, on the other hand, is thicker and less mobile, permeating the joints, organs, brain, and marrow, serving a nourishing function. Pathologically, there are distinctions between “injured Jin” and “lost Ye”; Jin can be easily replenished, while lost Ye is difficult to recover, thus clinical differentiation is necessary. Although Jin and Ye have certain differences, both originate from food and drink, generated in the middle burner (spleen and stomach), and are liquid substances flowing within the body. Therefore, in metabolic activities, they often complement and transform into each other, and pathologically, they frequently influence each other, hence they are often referred to collectively as body fluids without strict differentiation.Metabolism of Body FluidsThe metabolism of body fluids refers to the complex physiological processes of their generation, distribution, and excretion. This process involves the physiological functions of multiple organs and is the result of their coordinated interaction. The “Su Wen: Discussion on the Channels” briefly summarizes this process as: “Drinking enters the stomach, disperses essence and Qi, ascends to the spleen, where the spleen Qi disperses essence, ascends to the lungs, regulates the water pathways, and descends to the bladder. The water essence is distributed in four directions, and the five channels operate in parallel.”(1) Generation of Body FluidsBody fluids originate from food and drink, primarily generated through the Qi transformation activities of the spleen, stomach, large intestine, and small intestine. Specifically, after food and drink enter the stomach, they are digested and transported to the spleen, which, through its function of transportation and transformation, along with the small intestine’s role in separating clear from turbid, absorbs the liquid substances to produce body fluids. The large intestine also plays a role in body fluids by absorbing some moisture during the transformation of waste, forming solid stools. Thus, the generation of body fluids depends on two factors: sufficient intake of water-rich foods and the coordinated function of the spleen, stomach, small intestine, and large intestine. Therefore, if the spleen’s Qi transformation or the gastrointestinal absorption function is deficient or disordered, it will affect the generation of body fluids, leading to pathological changes due to insufficient body fluids.(2) Distribution of Body FluidsAfter body fluids are generated, their distribution within the body is completed through the coordination of the spleen, lungs, kidneys, liver, and the three burners.1. Role of the SpleenThe spleen governs the transportation and transformation of water and fluids. On one hand, it transports the body fluids absorbed by the stomach, small intestine, and large intestine upwards to the lungs through its ascending function, and then through the lung’s dispersing and descending functions, distributes them throughout the body; on the other hand, the spleen can also directly distribute body fluids to all parts of the body. If the spleen fails to function properly, the distribution and metabolism of body fluids will be obstructed, leading to symptoms such as phlegm retention, edema, and abdominal distension.2. Role of the LungsThe lungs govern the dispersing and descending functions, regulating the water pathways and serving as the upper source of water. After receiving the body fluids transported from the spleen, the lungs distribute them to the upper body and surface through their dispersing function, and to the lower body and internal organs through their descending function, while also transporting the turbid liquids produced by the organs to the kidneys and bladder. If the lung Qi’s dispersing and descending functions are abnormal, it will lead to obstruction in the water pathways, resulting in phlegm retention or edema.3. Role of the KidneysThe kidneys are the water organ and govern body fluids. They play a dominant role in the distribution of body fluids. The essence and Qi from the kidneys promote and regulate the entire metabolism of body fluids, as the spleen’s dispersing function, the lung’s regulation of water pathways, and the small intestine’s separation of clear from turbid all rely on the warmth of kidney Yang and the activation of kidney essence. Additionally, the kidneys themselves are also an important link in the distribution of body fluids. The turbid liquids produced by organ metabolism are transported downwards to the kidneys and bladder through the lung’s descending function, where the kidney’s Yang Qi vaporizes and reabsorbs the clear components for participation in the overall metabolism of body fluids, while the remaining turbid components are transformed into urine and excreted through the bladder. The kidney’s vaporization function adjusts the total amount of body fluids in the body based on the quantity of body fluids and the body’s needs by increasing or decreasing urine output. Therefore, deficiency of kidney Yang can also lead to obstruction in the distribution of body fluids, resulting in pathological changes such as edema.4. Role of the LiverThe liver governs the smooth flow of Qi and regulates the movement of body fluids, which relies on the promotion of Qi’s ascending and descending movements. When Qi flows smoothly, body fluids are distributed effectively. If the liver fails to regulate, Qi stagnation can occur, affecting the distribution of body fluids, leading to stagnation and symptoms such as phlegm retention, edema, and conditions like plum pit Qi, goiter, and abdominal distension.5. Role of the Three BurnersThe three burners serve as the channels for the distribution and movement of body fluids within the body. When the Qi transformation in the three burners is normal, the water pathways are unobstructed, ensuring that the various organs can distribute body fluids effectively. In summary, the distribution of body fluids within the body primarily depends on the spleen’s Qi transformation, the lung’s dispersing and descending functions, the kidney’s vaporization, the liver’s regulation, and the unobstructed water pathways of the three burners.(3) Excretion of Body FluidsAfter body fluids are distributed throughout the body and utilized, the excretion of residual moisture and metabolic waste is primarily the result of the cooperative functions of the lungs, kidneys, large intestine, and bladder. Since urine is the main pathway for the excretion of body fluids, the kidneys play an extremely important role in this process.1. UrineUrine is the primary pathway for the excretion of body fluids and is the final product of body fluid metabolism, containing waste materials produced by the body’s metabolism. The production and excretion of urine depend on the kidneys, which, through the vaporization of kidney Yang, transport the body fluids metabolized by the organs down to the kidneys or bladder, separating them into clear and turbid components. The clear components are reabsorbed by the body, while the turbid components become urine and are excreted through the bladder. Additionally, the vaporization of kidney Yang and the consolidating function of kidney Qi control the opening and closing of the bladder, regulating urine excretion. Of course, the production and excretion of urine are also related to the normal functions of the lungs, spleen, liver, and small intestine.2. Sweat and Water VaporThe lungs distribute body fluids to the surface of the skin through their dispersing function. After metabolism, body fluids can form sweat under the action of Qi’s vaporization. Additionally, during exhalation, the lungs can also expel some moisture in the form of water vapor from the respiratory tract. Therefore, sweat excretion and respiratory water vapor are also pathways for the excretion of body fluids.3. FecesThe large intestine receives food residues from the small intestine, absorbs the remaining moisture, and dries the waste to form feces for excretion. When the large intestine excretes feces, it also carries away some residual moisture, making it another pathway for the excretion of body fluids. Therefore, if there is too much residual moisture in the feces, it can lead to diarrhea; if there is too little, it can cause constipation.
In summary, the processes of generation, distribution, and excretion of body fluids are the results of the coordinated and close cooperation of multiple organs, with the lungs, spleen, and kidneys playing the most crucial roles. The lungs govern the dispersing and descending functions to regulate the water pathways, the spleen governs the transportation and transformation of body fluids, and the kidneys govern water. Zhang Jiebin summarized the roles of these three organs in the metabolism of body fluids as “the sign is in the lungs, the regulation is in the spleen, and the foundation is in the kidneys.” If the functions of the lungs, spleen, kidneys, and other related organs are disordered, it will affect the generation, distribution, and excretion of body fluids, disrupting the coordinated balance of body fluid metabolism, leading to insufficient generation of body fluids, excessive consumption, or obstruction in distribution and excretion, resulting in pathological changes such as phlegm retention and edema.Functions of Body FluidsThe physiological functions of body fluids mainly include moisturizing and nourishing, generating blood, regulating Yin and Yang, and excreting waste.1. Moisturizing and NourishingBody fluids contain a large amount of moisture and some nutrients, providing strong moisturizing and nourishing effects. They nourish the internal organs and tissues, as well as the skin, muscles, and hair. The body fluids distributed on the surface can nourish the skin and muscles, making them plump and shiny; the fluids that penetrate into the body can nourish the organs, maintaining their normal functions; the fluids that enter the orifices can keep the mouth, eyes, and nose moist; the fluids that flow into the joints can lubricate them, allowing for smooth movement; and the fluids that permeate the bones, spine, and brain can nourish the marrow. Therefore, if body fluids are insufficient, the moisturizing and nourishing functions will be impaired, affecting the physiological activities of the skin, muscles, orifices, joints, organs, and marrow, potentially damaging the physiological structure of the organs.2. Generating BloodBody fluids are an important component of blood, working together with Ying Qi to permeate the vessels and transform into blood, circulating throughout the body to exert their nourishing effects. As stated in the “Ling Shu: Abscesses and Carbuncles”: “The middle burner produces Qi like dew, which ascends to the valleys and permeates the vessels; body fluids harmonize and adjust, transforming into blood.” Body fluids also play a role in regulating blood concentration and maintaining circulating blood volume. When blood concentration is too high, body fluids can permeate into the vessels to dilute the blood and replenish blood volume; when the body is deficient in body fluids, the body fluids in the blood can also seep out of the vessels to replenish body fluids. Due to this mutual permeation and transformation between body fluids and blood, both originating from the essence of food and drink, it is said that “body fluids and blood share the same origin.”3. Regulating Yin and YangThe metabolism of body fluids plays an important role in regulating the Yin-Yang balance of the body. As a part of the body’s Yin fluids, sufficient body fluids can restrain excessive Yang heat and can be vaporized into sweat to dissipate body heat, thus regulating body temperature and maintaining the coordinated balance of Yin and Yang within the body. On the other hand, the metabolism of body fluids often changes with the body’s activities and the external environment. For example, as stated in the “Ling Shu: Five Types of Urine and Body Fluids”: “In cold weather, thin clothing leads to urination, while in hot weather, thick clothing leads to sweating,” indicating that the metabolism of body fluids adjusts the excretion of sweat and urine according to changes in external temperature, thereby regulating the body’s Yin-Yang balance and promoting adaptation to the external environment.4. Excreting WasteAfter metabolism, body fluids can carry various toxic waste products out of the body during excretion, thus playing a role in waste elimination and preventing the accumulation of toxic waste within the body, ensuring normal life activities. If the function of body fluids in waste excretion is disordered, abnormal sweating or urination can occur, leading to the retention of metabolic products in the body and resulting in various pathological changes. Additionally, body fluids also serve as carriers for Qi, facilitating the transport of Qi throughout the body. The Qi of the body must rely on tangible body fluids to circulate and distribute within the body to exert its effects.Relationship Between Qi and Body FluidsQi and body fluids are opposites; Qi is Yang, while body fluids are Yin. The relationship between Qi and body fluids is similar to that between Qi and blood, mainly manifested in several aspects: Qi can generate body fluids, Qi can move body fluids, Qi can control body fluids, and body fluids can carry Qi.(1) The Role of Qi on Body Fluids1. Qi Can Generate Body FluidsQi can generate body fluids, meaning that the vaporization function can promote the generation of body fluids, serving as the driving force for their production. Body fluids originate from food and drink, which undergo a series of physiological activities in the spleen and stomach, the small intestine’s separation of clear from turbid, and the large intestine’s role in governing body fluids, allowing the refined liquid portion to be absorbed by the body and transformed into body fluids for distribution. In the series of vaporization activities involved in the generation of body fluids, the Qi of many organs, especially the Qi of the spleen and stomach, plays a crucial role. If the Qi of the spleen and stomach is strong and the vaporization function is normal, the generation of body fluids will be sufficient; conversely, if the Qi of the spleen and stomach is weak, the vaporization function will be impaired, leading to insufficient generation of body fluids, which should be treated by tonifying Qi and generating body fluids.2. Qi Can Move Body FluidsQi can move body fluids, meaning that the movements of Qi’s ascending and descending can promote the distribution and excretion of body fluids, serving as the driving force for their normal circulation within the body. After body fluids are transformed by the spleen and stomach, they are propelled by the Qi of the spleen, lungs, kidneys, and three burners to be distributed throughout the body to exert their physiological effects. Additionally, through the Qi of the lungs, large intestine, kidneys, and bladder, the remaining moisture and metabolic waste after utilization are transformed into sweat and urine for excretion, thus maintaining physiological balance in body fluid metabolism. Therefore, if Qi is deficient and unable to promote movement, or if Qi stagnation occurs, it can lead to obstruction in the distribution and excretion of body fluids, resulting in water retention and the internal generation of phlegm, pathologically referred to as “Qi not moving water” or “Qi not transforming water.” Conversely, if for some reason the distribution and excretion of body fluids are obstructed, it will also adversely affect the movement of Qi, leading to stagnation of water and Qi. Therefore, in clinical treatment of conditions such as edema, it is common to combine methods of moving Qi and promoting water, tonifying the spleen and Qi, and dispelling dampness.3. Qi Can Control Body FluidsQi can control body fluids, preventing their unnecessary loss. The control of body fluids by Qi is achieved through the action of the Qi of various organs, such as the lung’s control over sweat, the kidney and bladder’s regulation of urine, and the spleen and kidney’s control over saliva and phlegm. Therefore, when the Qi of these organs is deficient, the control function will weaken, leading to abnormal loss of body fluids, resulting in symptoms such as excessive sweating, frequent urination, incontinence, or drooling and tearing. Treatment often involves tonifying Qi to control body fluids.(2) The Role of Body Fluids on Qi1. Body Fluids Can Carry QiBody fluids can carry Qi, meaning that body fluids also serve as carriers for Qi’s movement within the body. Qi must rely on tangible body fluids to exist within the body and be distributed throughout. Especially, the body fluids outside the vessels can carry defensive Qi, allowing it to reach the organs and surface of the body. As stated by Mo Meishi in the Qing Dynasty: “Nourishing Qi flows within the vessels, adhering to blood; defensive Qi flows outside the vessels, adhering to body fluids.” If the function of body fluids in carrying Qi is impaired, on one hand, excessive loss of body fluids due to sweating, vomiting, or diarrhea can lead to a significant loss of Qi, referred to as “Qi lost with body fluids.” On the other hand, when the distribution and movement of body fluids are obstructed, it often leads to stagnation of Qi, referred to as “body fluids stagnating Qi.”2. Body Fluids Can Generate QiBody fluids can generate Qi, meaning that body fluids can promote the generation of Qi, providing sufficient nourishment for its production. Body fluids nourish and moisten the organs related to Qi generation, such as the lungs, spleen, stomach, and kidneys, promoting their functional activities, thus ensuring the normal generation of Qi. In pathological conditions, prolonged deficiency of body fluids can also lead to secondary Qi deficiency.Relationship Between Blood and Body FluidsBlood and body fluids are both liquid substances that possess nourishing, moistening, and transporting functions, and both belong to Yin in contrast to Qi. Therefore, they mutually support and transform each other physiologically, and pathologically, they influence and affect each other, establishing a closer relationship.(1) The Role of Blood on Body FluidsBlood circulating within the vessels can seep out and transform into body fluids with moistening effects, nourishing the organs and orifices, and can also compensate for the deficiency of body fluids outside the vessels. Some of these body fluids can be transformed into sweat for excretion, hence the saying “blood and sweat share the same origin.” When blood is depleted, especially during blood loss, the reduced blood volume in the vessels cannot transform into body fluids, necessitating the entry of external body fluids into the vessels to compensate for the deficiency in blood volume, leading to a loss of body fluids outside the vessels, resulting in symptoms such as thirst, reduced urination, and dry skin. Therefore, for patients with blood loss, it is inadvisable to use sweating methods, as stated: “Those who lose blood should not sweat” (“Ling Shu: Meeting of Ying and Wei”), and “Patients with bleeding should not induce sweating” (“Shang Han Lun”).(2) The Role of Body Fluids on BloodBody fluids are one of the main components that generate blood. The body fluids produced from the transformation of food and drink by the spleen and stomach can ascend to the heart and lungs, entering the vessels and combining with Ying Qi to transform into blood. Additionally, the body fluids distributed in the muscles and superficial layers can continuously seep into the vessels to generate and replenish blood. Therefore, if body fluids are significantly depleted, not only will the body fluids entering the vessels decrease, but the liquid components within the vessels will also seep out more into the external environment, leading to a sudden reduction in blood volume and thickening of the blood, resulting in conditions such as blood vessel emptiness, body fluids drying up, or blood stasis due to body fluid deficiency. Thus, for patients with excessive sweating or significant loss of body fluids due to vomiting or diarrhea, it is not advisable to use harsh agents to break blood and eliminate stasis. This aligns with the saying in the “Ling Shu: Meeting of Ying and Wei”: “Those who lose sweat have no blood.”Blood and body fluids not only share the same origin and transform into each other, but also complement each other during their circulation and distribution processes. Body fluids can enter blood, and blood can become body fluids; “there is blood in water, and water in blood,” and “water and blood originally flow together without conflict” (“Blood Syndrome Theory: Theories of Yin, Yang, Water, Fire, Qi, and Blood”), both exerting their nourishing and moistening effects, hence the saying “body fluids and blood share the same origin.” Pathologically, blood and body fluids also influence each other; “if blood is not flowing well, it becomes water” (“Jin Gui Yao Lue: Water and Qi Disease Pulse Diagnosis and Treatment”), meaning that if blood flow is obstructed and stasis occurs, it can lead to obstruction in the distribution of body fluids, resulting in water retention and phlegm. Conversely, the internal generation of water retention and phlegm can also obstruct Qi and blood flow, leading to blood stasis. Therefore, traditional Chinese medicine also states that “phlegm and stasis are related.” Due to the frequent mutual influence and coexistence of blood and body fluids in pathological conditions, clinical treatment should also consider treating water diseases with blood treatments, blood diseases with water treatments, and addressing both water and blood together.