* The Concept of Blood
    * Body Fluids
    * Conection between Qi, Blood and Body Fluids
    * Disscussion of difficult points

1. The Concept of Blood
Blood is a thick red liquid circulating in the Blood vessels. It has a strong nourishing effect on the human body and serves as one of the basic substances constituting the human body. The vessels through which Blood circulates are also named the House of Blood. Under normal conditions, Blood circulates in the vessels so that it can reach each part of the body and produce its nourishing effect. In the case of extravasation of Blood, the Blood will fail to nourish the body; thus it is called extravasated Blood or dead Blood.

Although Blood in appearance is similar in TCM and Western medicine, it cannot be regarded in the same manner. In TCM, Blood is a Yin substance, so it depends on Qi to be generated and distributed. And Blood Deficiency is not equal to anemia. In most cases in TCM, anemia should be diagnosed as Deficiency of both Qi and Blood.

1-1. Formation of Blood
Blood is mainly composed of Nutritive Qi and Body Fluids, which come from the refined food transformed and transported by the Spleen and Stomach. So the Spleen and Stomach are also known as "the source of Qi and Blood", and the quality of the nutrients taken in, as well as the functional states of the Spleen and Stomach, influence directly the formation of Blood. The Essence stored in the Kidney can also be transformed into Blood by two methods. First, Kidney Essence and Liver Blood can be transformed into each other so that the Blood of the whole body is supplemented. Second, Kidney Essence supplies bones with marrow, which not only nourishes the bones but also generates Blood

1-2. Function of Blood
The main function of Blood is to nourish the whole body. Blood circulates ceaselessly through the vessels, by which it is carried to Zangfu Organs internally and to the skin, muscles, tendons and bones externally, to both nourish and moisten. Compared with Qi, Blood is a Yin substance which functions to support the body physique. Therefore, it serves as a Nutritive substance of the body. When the Blood is sufficient, there is a rosy and bright face, strong and well-developed muscles, and lustrous skin and hair. On the other hand, Deficiency of Blood will lead to withered hair and skin, atrophy and convulsion of tendons, thin muscles and weak Zangfu Organs.

Blood is also regarded as the material basis for mental activities, which are controlled by the Heart. As the Heart is in charge of Blood and vessels, the mental activities controlled by the Heart mainly take Heart Blood for their material basis. For this reason, sufficient Blood often exhibits as full vigor, perfect consciousness, keen perception, etc., while Deficiency of Blood usually leads to listlessness, insomnia, dream-disturbed sleep, dysphoria, or even vagueness of the Mind and other mental disorders.

1-3. Circulatiou of Blood
Blood, pertaining to Yin, is motionless in nature. It depends on Qi for its movement. But the circulation of Blood also requires the controlling of Qi in order to avoid extravasation. Therefore, coordination between the pushing action and controlling action of Qi maintains the normal flow of Blood. When the pushing action is excessive or the controlling action is too weak, the flow of Blood will be accelerated, or even will cause bleeding. Conversely, when Qi fails to propel or the controlling action of Qi is too excessive, the flow of Blood will become sluggish, or even develop into Blood Stasis. The circulation of Biood is related to the functional activities of all Five Zang Organs. The Heart controls the Blood of the whole body both by beating to give impetus to the Blood flow and by linking up the vessels. The Lung, which has the function of controlling Qi, helps the Heart to propel the Blood flow. In other words. the descending effect of the Lung can help send down Blood and the dispersing effect of the Lung can assist the outward flow of Blood. The Liver can maintain the free flow of Qi, so it also acts as one of the forces for the circulation of Blood. As for the control of the Blood flow, Spleen Qi and the Liver's Blood storage play an important role. Therefore, when Spleen Qi is deficient, bleeding will ensue as a result, while when the Liver fails to store Blood and regulate the distribution of Blood, bleeding will also occur.

The Cold and Heat of Blood also influence its circulation. Free flow of Blood depends on a certain temperature. Blood Heat, for example, may cause bleeding because the Heat will speed up the Blood flow, or cause Blood Stasis because the Heat may consume Body Fluids of the Blood and give rise to increased viscosity of Blood. Blood Cold, as a result of the contracting nature of Cold, will also impede the flow of Blood, causing Blood Stasis.

2. Body Fluids
Body Fluids is a general term for all the normal fluids of the human body, including the fluid existing in Zangfu Organs and tissues and the secretions and excretion of the human body. Like Qi and Blood, Body Fluids are also essential substances constituting the human body.

2-1. Formtlon, distributlou and discharge of Body Fluids
This is a rather complicated process involving the functional activities of a number of Zangfu Organs. Body Fluids are derived from the food and water taken in; their formation relies on the absorption of the water and nutrients of the food through the actions of the Stomach, the Small intestine and the Large intestine. To be exact, the Stomach absorbs part of the nutrients from food through its primary digesting action; the Small intestine separates nutrients from wastes to absorb the majority of the nutrients and fluid, and the large intestine absorbs the surplus of the food residues to form feces. The fluid absorbed by the Stomach, the Small intestine and the Large intestine is then sent to the Spleen to be distributed to the whole body. The distribution of Body Fluids depends on the action of tbe Lung, the Spleen and the Kidney and the San Jiao is necessary as the passageway. In other words, the Spleen can send Body Fluids up to the Lung so that they can be further distributed to other parts of the body. Besides, the Spleen can also distribute Body Fluids directly to other parts of the body. Therefore, the Spleen plays a very important role in the distribution of Body Fluids, and failure of the Spleen in transformation and transportation is considered the most important reason behind the occurrence of Phlegm, water retention and edema.

The Lung has the effect of regulating the metabolism of Body Fluids. Through its dispersing effect, Body Fluids can be sent to moisten the skin and muscles and be transformed into sweat to be discharged while through its descending effect, Body Fluids can be sent down to the Bladder and other parts of the lower body. Disturbance of the Lung's dispersing and descending action will certainly cause disturbance of the distribution and discharge of Body Fluids, giving rise to Phlegm, edema, or urine disorders. The Kidney exerts its influence on Body Fluids in two ways: first, its Yang Qi warms up Yang Qi of the whole body to promote the distribution and discharge of Body Fluids; secondly, it controls the formation and discharge of urine is the most important means of discharging Body Fluids. In brief, the formation of Body Fluids mainly depends on the transformation and transportation of the Spleen and Stomach; their distribution depends on the Spleen and the Lung, and their discharge depends on the Lung and the Kidney.

2-2. Functions of Body Fluids
As liquid substances, Body Fluids function to moisten and nourish the human body. Compared with Blood, the nourishing effect of Body Fluids is not so strong. To be exact, when distributed in the body surface, they moisten the muscles, skin and hair; when permeating through the body orifices, they moisten and protect the nose, eyes, ears and mouth when infiltrating the vessels, they nourishes and smooth the vessels as the basic component of Blood when pouring into the internal organs, they nourish and moisten them; and when seeping into the joint cavities, marrow cavity and skull, they lubricate the joints, nourish and moisten the bone marrrow, spinal cord and the brain. When Body Fluids are deficient, these areas or organs will become dry or withered.

3. Connections Between Qi, Blood and Body Fluids
As the basic substances of the human body, Qi, Blood and Body Fluids are closely related to each other. They are all derived from food Essence and assist, depend on, and are transformed into each other.

3-1. Connection between Qi and Blood
The relation of Qi and Blood can be generalized as having two aspects: Qi as the commander of Blood, and Blood as the mother of Qi.

As the commander of Blood, Qi has three main functions.

One, generating Blood. This means that the generation of Blood depends on Qi's activities for its production. Blood is composed of Body Fluids and Nutritive Qi, which is produced by food through the functional activities of Spleen Qi and Stomach Qi. During this process, it is Qi's activities that transform the food into food Essence, then into Nutritive Qi and Body Fluids and ending in the formation of Blood. Without Qi's activities, there would be no Blood. So Qi can generate Blood. When Qi is vigorous, it can generate adequate Blood. On the other hand, Deficiency of Qi will cause Blood Deficiency due to decline of its action of generating Blood. Clinically, Qi-invigorating drug are often added to Blood-nourishing formulas to promote the generation of Biood.

Two, propelling the circulation of Blood. This means that Blood, a Yin substance which is motionless in nature, depends on Qi for its movement. To be exact, Heart Qi moves Blood by maintaining the beating of the Heart, Lung Qi pushes Blood outward through its dispersing effect and sends down Blood through its descending effect, and the Liver's dispersing and discharging effects help to regulate the free flow of Blood. When Qi is deficient and hasn't enough power to propel, the Blood flow will become sluggish or Blood Stasis will occur. If Qi's ascent, descent, or entry and exit movements are destroyed, Blood Flow will also be disturbed. For example, adverse upward flow of Qi will cause Blood to flow upward excessively, giving rise to distending pain of the head, blood, shot eyes, red face, or even hematemesis and coma. Therefore, Blood flow disorders are usually treated both with drugs regulating Blood and drugs regulating flow of Qi.

Third, controlling the flow of Blood. This means that Qi functions to keep Blood flowing within the vessels to prevent extravasation, which is mainly performed by Spleen Qi. If Qi fails to control Blood flow, various kinds of bleeding will occur. Clinically, bleeding due to Qi Deficiency must be treated by strengthening the Spleen so that Blood flow can be controlled. Blood as the mother of Qi has two meanings: Qi attaching to Blood and Blood supplying Qi. Qi is a vigorous substance and prone to flee easily, so it must attach itself to Blood so that it can reach all of its distribution points to perform its normal function. This is also a manifestation of mutual restriction of Yin and Yang, or the motionless nature of Blood restricting the moving nature of Qi. By Blood supplying Qi is meant that Blood nourishes Qi or serves as the material basis of Qi. Clinically, a severe hemorrhage often gives rise to escape of Qi due to the failure of Blood to carry Qi, and Blood Deficiency often leads to Qi Deficiency.

3-2.Relationship between Qi and Body Flulds
The relations of Qi and Body Fluids is very similar to those of Qi and Blood. The generation, distribution and discharge of Body Fiuids depend on Qi and its activities. On the other hand, Qi also relies on Body Fluids to be carried, and Body Fluids are where Qi exists, moves and changes. Qi can generate Body Fluids. Body Fluids comes from food and drink, which are transformed into both refined and waste material through the activities of the Spleen and Stomach. The liquid that has been refined, or Body Fluids, is then distributed to each part of the body by the Spleen. When the Spleen and the Stomach function properly, Body Fluids can be adequately generated on the other hand, Deficiency of Spleen Qi or Stomach Qi will lead to inadequate formation of Body Fluids, causing Deficiency of both Qi and Yin Fluids.

Qi can distribute and transform Body Fluids. Body Fluids are substantial and motionless in nature. So their distribution and discharge depend on the propulsion of Qi and the activities of Qi. As a result of the ascent, descent, and entry and exit movements of Qi of the Spleen, the Lung and the Kidney, Body Fluids are distributed all over the body to perform their moistening effect. All the metabolized Body Fluids must be transformed into sweat, urine or steam to be discharged, so the transforming effect of Qi plays an important part in the discharge of Body Fluids. Failure of Qi to propel and transform due to its Deficiency or to stagnation of Qi can give rise to retention of Body Fluids, leading to edema, Damp or Phlegm, which is known as inability of Qi to propel and transform Body Fluids.

Qi can control Body Fluids. This means that Qi can control the flow and discharge of Body Fluids to prevent their excessive loss. For example, Defensive Qi can prevent excessive sweating by controlling the closing and opening movements of the sweat pores. If Defensive Qi is deficient, spontaneous sweating will occur as a result; Kidney Qi controls the opening and closing of the Bladder, so Deficiency of Kidney Qi often leads to profuse and frequent urine, enuresis and incontinence of urine. For such cases, drugs consolidating Qi must be adopted to obtain effectiveness.

Body Fluids carry Qi. Qi is also attached to Body Fluids. When too much Body Fluids are lost, Qi will escape. Excessive vomiting or diarrhea, for example, will impair Qi, leading to Deficiency of Qi, which is often accompanied by lassitude, a symptom of Qi Deficiency.

3-3. Relationship between Blood and Body Fluids
Blood and Body Fluids are from the same source and their functions are similar. So they can be transformed into each other and are closely related to each other. Both Blood and Body Fluids are derived from food Essence, hence they are said to have "a common source'. Body Fluids are an important component of Blood, and Body Fluids in the vessels can go out of the vessels to make up Body Fluids of the body and vice versa, so Blood and Body Fluids usually influence each other under pathologic conditions. When excessive loss of Blood occurs, Body Fluids that are out of the vessels can enter the vessels to compensate for the loss in the same way, when there is excessive consumption of Body Fluids, the Fluids in the vessels can also go out of the vessels to increase those Body Fluids. Therefore, for patients with excessive bleeding, diaphoretic should be avoided; while for patients with Deficiency of Body Fluids, the practice of removing Blood Stasis with drastic drugs is not indicated.

4. Discussion of Difficult Points
4-1. Difference between Qi and Essence QI
Qi and Essence Qi are two frequently used terms in TCM, and they are often used interchangeably because they have many things in common. But they have different meanings.

In the very beginning, both Qi and Essence Qi were used to imply the basic substance of the world. Afterwards, only Qi was used in this sense and Essence Qi was limited to the following meanings: First, a substance that is extremely minute. As Essence literally suggests, Essence Qi is one kind of refined substance which is used to create or form more advanced things. In ancient China, there was the saying that "Essence Qi produces man and turbid Qi produces animals". As the Essence stored in the Kidney is the basis of the growth and development of the human body, it is also called Essence Qi.

Second, a substance that is nutritive. The ancients believed that things of high quality must be more useful than those of lower quality. So compared with the raw materials or food, the nutrients of the body such as the Blood, Body Fluids and the Qi of the human body, can all be said to be Essence Qi. For example, we often say the main function of the five Zang Organs is to store Essence Qi, which here means the nutritive substances that are necessary for the life activities of the human body.

Third, a substance that is useful. Man depends on the nourishment of both Heaven Qi and Earth Qi, but not everything in nature is useful for human beings. Only the things that can support human life are what the human body requires. So in TCM, we call these useful substances from nature Essence Qi of the Heaven aid the Earth. Food is essential to the human body, but only the nutritive parts of the food share the name of Essence Qi of Food and Drinks. Currently, Essence Qi basically has only the above three meanings.

4-2. Why doesn't TCM stress tlte concrete process of the formation of Blood
As mentioned in this chapter, Blood, according to TCM theory, is formed in two ways: combination of Nutritive Qi and Body Fluids which enter the vessels together under the action of Nutritive qi, and the production of Blood from the Essence stored in the kidney. During the process of the formation of Blood, the Spleen, which produces Nutritive Qi and the Body Fluids, the Kidney, which stores Essence and food which serves as the source of Nutritive Qi and Body Fluids are the main contributing factors. As for how Nutritive Qi combines with Body Fluids to produce Blood or how Kidney Essence transforms into Blood, TCM gives no exact answers. Why?

This question is related to the characteristics of TCM theories. We know that the theories of TCM originate from clinical practice and their value is that they can be guides to that clinical practice. This is quite different from theories in Western medicine which are based on anatomical or analytical methods. In TCM, answers to questions are necessary only to the extent that they can guide clinical practice. In the clinic, strengthening the Spleen to enhance its transforming and transporting effects and to produce more Nutritive Qi and Body Fluids, and to nourish Kidney Essence to promote the transformation of the Blood have long been proved to be the most effective way for treating a Blood Deficiency. No matter how carefully the formation of Blood is analyzed, as long as it cannot guide clinical practice, it is not useful in TCM, and therefore, further exploration is not required.

4-3. What is the significance of stressing the relationship between Qi and Blood?
In Western medicine, there is no concept such as Qi. So blood disorders, including inadequate production of the blood as in aplastic anemia, and leukopenias are treated as only relative diseases of blood. But in TCM, which stresses the existence of Yin and Yang in the human body, Qi and Blood have close relations, which are known as Qi being the master of Blood, and Blood being the master of Qi. This kind of relation not only determines the understanding of TCM of the formation and the circulation of Blood, but also influences the diagnosis and treatment of Biood disorders. For example, Blood Deficiency may be caused by Qi Deficiency which cannot generate Blood, since Qi is the motive force for Blood generation. In the treatment of such Blood Deficiency, supplementing Qi plays an even more important role than nourishing Blood. Bleeding, for another example, may be the result of Qi Deficiency because Qi controls Blood flow, so such bleeding should be treated by strengthening Qi.

Patients with anemia niay be misdiagnosed only as having Blood Deficiency in the clinic, because one may take blood in Western medicine and Blood in TCM as the same. Anemia is a disease caused by reduction of the oxygen carried by the hemoglobin, while Blood Deficiency in TCM means a morbid state which is caused by loss of Blood and results in the decline of the nourishing effect of the Blood. In fact, most anemia patients present the symptoms of both Qi Deficiency and Blood Deficiency in accordance with TCM theory, and are treated mainly by supplementing qi.

Please browse the following contents for further study:

1. Disease Prevention
2. Effective Herbal Formulas for Treating Cancer
3. Effective Herbal Formulas for Treating Neurological System Diseases
4. Effective Herbal Formulas for Treating Mental Disorder
5. The Concept of Qi(qi),
6. The Concept of Blood, Body fluid and Qi
7. DaMo Qigong Chinese Medicine World
8. Inner Canon of Yellow Emperor
9. Treatise on Cold-induced Febrile Diseases
10. Mechnism of Yin-yang Operation
11. Five Element System
12. Visceral Symptoms
13. Pathogenic Factors
14. Mechnism of Chinese massage
15. The Acupuncture treatment Principle
16. Famous Chinese Doctors and works
17. The theory of external Qi therapy
18. The history and origin of Chinese acupuncture
19. The general introduction of meridians and channels
20. DaMo Qigong Chinese Medicine World