Body Fluids from a TCM Perspective
Body fluids refer to the different kinds of physiological fluids found in the body, including fluids in the organs and tissues, gastric fluid, intestinal fluid, semen and tears. Classified as one of the fundamental substances, body fluids are essential to life activities.
All physiological fluids come from the same source that produced by the spleen and stomach, however, due to their textures, functions and distributions, TCM classifies them into two major types. The first type refers to the fluids that are thin and clear in textures, and tend to flowing around; these thin body fluids usually distribute in the skin, muscles and orifices for moistening purpose, they also infuse into blood vessels to be part of the blood components. The second type refers to the fluids that are thick and sticky in textures, and tend to stay in fixed places, such as fluids irrigating the joints, organs, brain and bone marrow; these thick body fluids are mainly for nourishment purpose.
Origin, Distribution and Excretion of Body Fluids
Metabolism of body fluids, including formation, distribution and excretion, involves complicated processes, which are mainly coordinated mutually through organs such as the lungs, spleen, kidneys, bladder and triple burner. Body fluids are originated from ingested food and drinks. They are broken down in the stomach, where part of the nutrients are absorbed and sent to the spleen, the remaining mixtures will send to the small intestine for separation. The small intestine absorbs the useful nutrients and pure fluids and send them to the spleen, the impure and undigested parts will pass into the large intestine, where absorbs more water and forms the stool for excretion.
The transportations and distributions of body fluids are mainly organized by organs such as the spleen, lungs, kidneys and liver, and through the passages of the triple burner. They work together to make sure the body fluids distributing or spreading to the entire body, reaching externally to the skin and body hairs, and also irrigating throughout the internal organs.
- The spleen spreads essence: when the spleen received nutrients and fluids from the stomach and intestines, it will transform into different body fluids. In one hand, the spleen will use its transportation function to distribute some body fluids to the whole body. On the other hand, it will transport the body fluids upward to the lungs.
- The lungs govern movement of water, regulates water passages, and is regarded as the upper fluid source of the body. When the lungs received the body fluids from the spleen, it will use its rising and growth functions to distribute the body fluids to the upper body as well as body surface for nourishment and moistening; also it will vaporize the excess fluids into sweat and excrete through skin. In addition, the lungs will use its purification and down-sending functions to send the body fluids to the kidneys and bladder, and also distribute the body fluids to the lower body. In the kidneys and bladder, excess or used fluids will transform into urine for excretion.
- The kidneys govern water, which is critical for the distribution of body fluids. Kidney yang has steaming and promoting properties, in TCM it is regarded as the power source for organ functioning. The stomach, spleen, lungs, or intestines are all relied on kidney’s promoting force to work continuously. The kidneys also involve in the distribution of body fluids directly; it separates the body fluids into pure and impure forms, and then sends the pure fluids to the lung, and the impure fluids to the bladder to be excreted. The formation and excretion of urine is important for the balancing of body fluid metabolism.
Body fluids are excreted via different pathways, such as expiration, sweating, urination and defecation, which are the end processes of its metabolism. In this way, body fluids help excrete metabolic wastes and excess water produced through the functions of various organs, and so maintain a clean and healthy environment for organs, meridians and tissues.
There are two major reasons to cause abnormal fluid metabolism. Firstly, the body has insufficient blood formation or over consumption of blood; secondly there is dysfunction of distributing or excreting body fluids that lead to internal fluid retention and in turn generates pathological products like dampness and phlegm. TCM usually views the problems as abnormal qi movements or qi transforming of organs like the lungs, spleen, kidneys, liver and triple burner. Any factor that interrupted these organ functioning will develop fluid-related disharmonies, such as urinary difficulty, puffiness, dampness stagnation, damp turbidity and fluid retentions. Moreover, when the liver fails to regulating qi, or the water passages in triple burner are blocked, the body will generate excessive phlegm, which not only affects body fluid metabolism, but also interrupt the blood and qi conditions, leading to more complicated health problems.
Functions of Body Fluids
Body fluids are one of the fundamental substances of body, and are indispensable to life activities. The functions of body fluids can be summarized as below: 1. Providing moisture and nourishment
Body fluids are mainly composed of water, and also contain various nutrient substances, thus they have strong moistening and nourishing effects. When distributed to the surface of the body, body fluids moisten the skin and hair and maintain the smooth and elastic texture of the skin. Body fluids also moisten, nourish and protect different orifices in the body. For example, body fluids allow the eyelids to blink smoothly, the nasal cavity to maintain an open airway without blockage and the lips and mouth to remain moist without becoming dry. Internal body fluids also penetrate different organs, tissues and even bone marrow to provide moisture and nourishment. The spinal cord and brain are examples of organs surrounded by body fluid that protects and nourishes them.
When body fluids can no longer nourish and provide moisture to the body, symptoms such as dry skin, flaccid muscles, brittle hair, dry eyes, parched lips a dry nose or throat, dry stools and scanty urine occur. More seriously, since body fluids are important yin components of the body, a long term depletion of body fluids will cause the body’s yang components over-acting and generating virtual fire internally, heat signs like hot flush, red cheeks, night sweat, and vexing heat in the chest, palms and soles will be developed.
2. Transforming blood
Through the minute collaterals, body fluids infuse into blood vessels, and combine with nutrient qi to become the source of blood formation. In case if there is a major blood loss, body fluids will infuse into blood vessel for replenishment, and help keep an effective blood circulation. For conditions with severe sweating, vomiting, diarrhea or high fever, the body has already lost a lot of body fluids, and this usually follows by a declined blood volume. It is always contraindicated to apply with perspiration therapeutic method, in order to avoid further aggravation.
3. Regulating yin yang balance
Body fluids are important yin components of body, which referred to collectively as “yin essence” in TCM. Body fluids can be regulated according to the needs of internal body or external environmental changes, so as to make the body more adaptable. For example, during cold season or not enough clothing, the skin pores will be closed, so as to reduced body sweating and keep warm. However, during hot season or too much clothing, striae in the skin and muscles will become loosen, the body can sweat easily and release its excess heat. In this way, the body keeps in a stable internal environment to support life activities.
4. Excreting body wastes
Body fluids involve in various organ functions, they carry the metabolic wastes and excrete them via different pathways like sweating and urination. This ensures a clean and harmonized internal environment, and facilitates normal functioning of organs and tissues.
Clinically, when physicians evaluate a disharmony of body fluid deficiency, they will first identify whether the pathological changes are due to “moistening fluid depletion” or “nourishing fluid depletion.” Situations for moistening fluid depletion usually occur in too much sweating, dry season, vomiting, or diarrhea, that make the patients present thirst, dry skin, dry nose, and even sinking eyeballs. On the other hand, situations for nourishing fluid depletion usually occur after feverish conditions, chronic or major diseases, that make the patients present a red tongue without coating, mouth dryness but don’t have a desire for drinking, skinny body, shrunken skin, and even developing muscular twitching, cramps and shaking, which TCM claims were due to a pathological state named deficient wind stirring inside.
The reason for the above clarifications is to facilitate treatment. Conditions with moistening fluid depletion are not difficult to recover; physicians usually focus on tonifying the lungs and stomach, and will select herbs with sweet flavor and cold property, a sample of prescriptions is Glehnia Root and Dwarf Lily-turf Tuber Decoction (sha shen mai dong tang). Conditions with nourishing fluid depletion are not easy to recover instantly, physicians will aim to invigorate the liver and kidneys, and select herbs with salty flavor, and cool property, a sample of prescriptions is Great Tonify the Yin Pill (da bu yin wan).
Body fluids metabolism from a TCM perspective
References
- 張恩勤：《中醫基礎理論》上冊，上海中醫藥大學出版社，1990。
- 劉家義等：《中醫診斷學》上海中醫藥大學出版社，1990。
- 北京中醫學院：《中醫學基礎》第一版，上海科學技術出版社，1978。
- 4. 印會河：《中醫基礎理論》上海科學技術出版社，1985。
- 5. 《黃帝內經素問》北京人民衛生出版社，1978。
- 劉燕池：《中醫基礎理論問答》第一版，上海科學技術出版社，1982。
- Kaptchuk Ted J., Chinese Medicine :The Web That Has No Weaver, London: Rider, (2000).
- Williams Tom, Complete Chinese Medicine, Bath: Mustard, (1999).
Written By:
Dang Yi, Professor, Beijing University of Chinese Medicine Ph.D.Beijing Union Medical College Vice Director,
Gourmet Food Institute of Health Care and Nutrition of Beijing
Edited By:
Angelo Chung, B Pharrm., Integrated Chinese Medicine Holdings Ltd.Angela Collingwood, MSN, Integrated Chinese Medicine Holdings Ltd.
Margaret Harris, MD, Integrated Chinese Medicine Holdings Ltd.
