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Comprehensive TCM Treatments for Common Diseases
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Concept of Body FluidsBody fluids (津液, jīnyè) refer to all normal fluids in the body and are fundamental substances that constitute and maintain life activities. Body fluids are considered yin in nature, hence also referred to as “yin fluids” (阴津, yīnjīn) or “yin liquids” (阴液, yīnyè). The term encompasses a wide range of fluids, 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 become components of blood, while outside the vessels, they permeate the organs and interstitial spaces.
Body fluids are a collective term for “津” (jīn) and “液” (yè), which have certain differences in properties, distribution, and functions. Physiologically, “津” is lighter and more fluid, primarily distributed in the skin, muscles, and orifices, serving a moistening function and can permeate into the blood to generate blood. In contrast, “液” is thicker and less fluid, filling the joints, organs, brain, and marrow, serving a nourishing function. Pathologically, there are distinctions between “injured fluids” and “lost liquids”; fluids are easier to replenish, while liquids are harder to recover. During clinical differentiation, this distinction should be made. Although “津” and “液” have certain differences, both originate from food and water, generated in the middle jiao (中焦, zhōngjiāo) of the spleen and stomach, and are both liquid substances flowing within the body. Therefore, in metabolic activities, they often supplement and transform into each other, and pathologically, they often influence each other, hence they are commonly referred to together without strict differentiation.Metabolism of Body FluidsMetabolism of body fluids refers to the complex physiological processes of generation, distribution, and excretion of body fluids. This process involves the physiological functions of multiple organs and is the result of their coordinated interaction. The “Su Wen: Discussion on Meridians” 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. Water essence is distributed in four directions, and the five meridians operate concurrently.”(1) Generation of Body FluidsBody fluids originate from food and water, 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 process of transforming waste, thus forming feces. Therefore, 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. 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 conditions of fluid deficiency.(2) Distribution of Body FluidsAfter body fluids are generated, their distribution within the body is completed with the coordination of the spleen, lungs, kidneys, liver, and the three jiaos (三焦, sān jiāo).1. Role of the SpleenThe spleen governs the transportation and transformation of water and fluids. On one hand, it uses its ascending and clarifying power to transport the fluids absorbed by the stomach, small intestine, and large intestine upwards to the lungs, 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 fluids to all parts of the body. The “Su Wen: Discussion on the True Organs” states that the spleen has the physiological function of “nourishing all sides.” If the spleen loses its healthy function, the distribution and metabolism of body fluids will be obstructed, leading to symptoms such as phlegm, edema, and fullness.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 the lungs receive the body fluids transported from the spleen, they disperse the fluids to the upper body and surface through their dispersing function, and descend the fluids to the lower body and internal organs, transporting the turbid liquids produced by the organs to the kidneys and bladder. If the lung qi’s dispersing and descending functions are abnormal, the regulation of the water pathways will be impaired, leading to fluid stagnation and resulting in phlegm or edema.3. Role of the KidneysThe kidneys are the water organ and govern body fluids (“Su Wen: Discussion on Reversal”), playing a dominant role in the distribution of body fluids. On one hand, the essence and qi in the kidneys promote and regulate the entire metabolism of body fluids, as the spleen’s dispersing essence, 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. On the other hand, 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, and the kidney’s yang qi vaporizes and transforms them, allowing the clear portion to be reabsorbed into the overall fluid metabolism, while the remaining turbid portion is transformed into urine and excreted. The kidney’s vaporization function adjusts the total amount of body fluids based on the body’s needs by increasing or decreasing urine output. Therefore, deficiency of kidney yang can also lead to distribution disorders 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. The distribution of body fluids relies on the movement of qi. When qi flows, body fluids are distributed, promoting their circulation. If the liver fails to regulate, qi stagnation often affects the distribution of body fluids, leading to stagnation and resulting in symptoms such as phlegm, edema, and conditions like plum pit qi, goiter, and abdominal distension.5. Role of the Three JiaosThe three jiaos serve as the channels for the distribution and movement of body fluids within the body. When the qi transformation in the three jiaos is normal, the water pathways are unobstructed, ensuring that the various organs can distribute body fluids smoothly. In summary, the distribution of body fluids within the body primarily relies on the spleen’s transportation, the lung’s dispersing, the kidney’s vaporization, the liver’s regulation, and the unobstructed water pathways of the three jiaos.(3) Excretion of Body FluidsAfter body fluids are distributed throughout the body and utilized, the excretion of remaining 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 fluid metabolism, containing waste materials produced by the body’s metabolism. The production and excretion of urine depend on the kidneys, which vaporize the fluids after organ metabolism and transport them down to the kidneys or bladder, separating them into clear and turbid portions. The clear portion is reabsorbed by the body, while the turbid portion becomes urine and is excreted. Additionally, the kidney’s qi transformation and the controlling function of kidney qi regulate the opening and closing of the bladder, adjusting 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 be transformed into sweat and excreted through the skin due to the vaporization effect of qi. 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, excessive residual moisture in feces can lead to diarrhea, while insufficient residual moisture 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 of body fluids, and the kidneys govern water. Zhang Jiebin summarized the roles of these three organs in fluid metabolism 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 fluid metabolism, leading to insufficient generation of body fluids, excessive consumption, or obstruction in distribution and excretion, resulting in pathological changes such as phlegm and edema.Functions of Body FluidsThe physiological functions of body fluids primarily include moistening and nourishing, generating blood, regulating yin and yang, and excreting waste.1. Moistening and NourishingBody fluids contain a large amount of moisture and some nutrients, providing strong moistening and nourishing effects. They nourish the internal organs and tissues, as well as the skin and muscles. The body fluids distributed on the surface can nourish the skin and muscles, making them plump and the hair shiny; the fluids penetrating into the body can nourish the organs, maintaining their normal functions; the fluids entering the orifices can moisten the mouth, eyes, and nose; the fluids flowing into the joints can lubricate them, allowing for smooth movement; and the fluids permeating the bones, spine, and brain can nourish the bone marrow, spinal cord, and brain. Therefore, if body fluids are insufficient, the moistening and nourishing functions will be impaired, affecting the physiological activities of the skin, muscles, orifices, joints, organs, and even the physiological structure of the organs.2. Generating BloodBody fluids are an important component of blood, and together with the nutritive qi, they permeate the vessels and transform into blood, circulating throughout the body to exert their nourishing effects. As stated in the “Ling Shu: Abscesses and Sores,” “The middle jiao produces qi like dew, which ascends to the valleys and permeates the vessels; body fluids harmonize and transform 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 penetration and transformation between body fluids and blood, both originating from the essence of food and water, there is a saying 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 and 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. As stated in the “Ling Shu: Five Types of Body Fluids,” “In cold weather, thin clothing leads to urination and qi; 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 and 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 the excretion process, thus playing a role in waste excretion and preventing the accumulation of toxic waste within the body, ensuring normal life activities. If the function of body fluids in excreting waste is disordered, abnormal sweating or urination can lead to the retention of metabolic products in the body, resulting in various pathological changes. Additionally, body fluids also serve as carriers of qi, facilitating the transport of qi throughout the body. The body’s qi 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 effect can promote the generation of body fluids, serving as the driving force for their production. Body fluids originate from food and water, which undergo a series of physiological activities in the spleen and stomach, small intestine, and large intestine, where the refined liquid portion is absorbed by the body to generate body fluids for distribution throughout. In the series of qi transformation activities involved in the generation of body fluids, the qi of various 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 body will generate sufficient body fluids; conversely, if the qi of the spleen and stomach is weak, the vaporization function will be diminished, leading to pathological changes of insufficient body fluids, which should be treated with methods to tonify qi and generate body fluids.2. Qi Can Move Body FluidsQi can move body fluids, meaning that the movement of qi 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 generated by the spleen and stomach, they are propelled by the qi of the spleen, lungs, kidneys, and three jiaos to distribute 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 fluid metabolism. Therefore, if qi is deficient and unable to propel, or if qi stagnation occurs, it can lead to obstruction in the distribution and excretion of body fluids, resulting in water retention and the generation of phlegm, a pathological condition 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 controlling function is weakened, 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 to circulate within the body. Qi must rely on tangible body fluids to exist within the body and distribute 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, “The nourishing qi flows within the vessels, adhering to the blood; the defensive qi flows outside the vessels, adhering to the 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 stagnate and obstruct qi.”
2. Body Fluids Can Generate QiBody fluids can generate qi, meaning that body fluids can promote the generation of qi, providing sufficient nutrition 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 symptoms of qi deficiency.Relationship Between Blood and Body FluidsBlood and body fluids are both liquid substances that possess moistening, nourishing, and transporting functions, and both are considered yin in relation 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 tissues, and compensating for any deficiency of body fluids outside the vessels. Some of the body fluids can also transform 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, 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: Discussion on Nourishing and Protecting”).(2) The Role of Body Fluids on BloodBody fluids are one of the main components that generate blood. The body fluids generated from the transformation of food and water in the spleen and stomach can ascend to the heart and lungs, entering the vessels and combining with the nutritive qi to transform into blood. Additionally, body fluids distributed in the muscles and skin 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, dry body fluids, or blood stasis due to 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 blood-breaking or stasis-removing medications. This aligns with the saying in the “Ling Shu: Discussion on Nourishing and Protecting” that “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 circulation and distribution. Body fluids can enter blood, and blood can become body fluids, as expressed in the saying, “there is blood in water, and water in blood,” and “water and blood run parallel without conflict” (“Discussion on Blood Conditions: 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.” In pathological conditions, blood and body fluids also influence each other; “if blood does not flow well, it becomes water” (“Jin Kui Yao Lue: Water and Qi Disease Pulse Diagnosis and Treatment”), meaning that poor blood circulation and stasis 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, TCM also recognizes the relationship between phlegm and stasis. Due to the frequent mutual influence 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.