Section 3 The Pathological Mechanism of Five Endogenous Evlis
Section 3 The Pathological Mechanism of Five Endogenous Evlis
The six climatic evils--wind, cold, summer-heat, dampness, dryness, and fire, are considered to be the causative factors of exogenous diseases in the etiology of traditional Chinese medicine, which is mainly based upon the pathological influences on the human body by abnormal changes of the six climates in the natural world. These pathogenic evils are from the external environment, and therefore are attributable to the realm of etiology. The "five endogenous evils" refer to five kinds of pathological states caused by disturbances of the visceral functions of the body itself in the course of disease development.However, they are manifested in their transformation into wind, cold, dryness, fire, and producing dampness. Since these disorders originate in the inner body, they belong to the field of pathological mechanism.
When traditional Chinese medicine attempts to understand and summarize the pathological changes in clinical practice, a certain number of natural phenomena and clinical manifestations of disease are connected in order to explain complex pathological changes. For example, stirring up wind, or wind-stroke, is termed "wind disease. " The reason for this is that the condition is marked by dizziness, vertigo, deviation of the eyes and mouth, clenched jaw, opisthotonos, convulsive spasm of the limbs, and tremor, all of which seem to be determined by the characteristics of the rage, migration, and rapidity and variability of wind-qi. As matter of fact, these pathological reactions are the results of disturbances of the visceral function, but are not caused by wind-evil from the external environment. In order to distinguish this etiological concept, it is therefore known as "endogenous wind" or "wind-qi stirring within. The other endogenous evils are called "endogenous cold," "endogenous damp," "endogenous dryness" and "endogenous fire" acicordingly. Hence, the so-called the five endogenous evils are by no means pathogenic factors, but rather systematic pathological changes caused by disturbances of physiological functions of the qi, blood, body fluids and viscera.
I. Wind-Qi Stirring Within
This phrase refers to a pathological state of ascendant hyperactivity and stirring up of yang-qi of the liver. It is also called "liver-wind stirring within. " Thus, the Cases Studies for Clinical Guidance states: "Endogenous wind results from the movement of the body's yang-qi. " It may occur in cases of ascendant hyperactivity and up-stirring of yang-qi due to exuberant yang, or it may also be caused by a failure of deficient yin to check yang. This is characterized by the sudden appearance of shaking, dizziness, vertigo, convulsive spasms, and tremor. Such a condition is a concrete manifestation of wind-qi stirring within in the course of disease. Thus, chapter 74 in Plain Questions states: "Syndromes characterized by the sudden onset of rigidity are related to the wind. Syndromes haracterized by shaking, dizziness, and vertigo are related to the liver. " This is because he liver stores the blood, dominates the tendons, and opens into the eyes, and liver-yang
is prone to hyperactivity and moving.
The types of wind-qi stirring within may be summarized as transformation of liver-yang into wind, extreme heat causing wind, endogenous wind produced by deficient yin,and blood deficiency causing wind.
1. Transformation of Liver-Yang into Wind
This may occur most commonly in cases of yin consumption of the liver and kidney
due to internal injury from emotional factors or over-fatigue. The result is ascendant hyperactivity of yang due to yin deficiency, i.e. water failing to nourish wood, and the failure of floating-yang in hiding, which is then transformed into the syndrome of wind-qi stirring within. In a mild case, muscular twitching and cramping, numbness, tremor of the limbs, vertigo, deviation of the mouth and eyes, or hemiplegia may occur. In more severe cases, blood circulation following the counter-flow of qi leads to the patient's sudten falling down in a fit, and closure syndrome or collapse syndrome may appear. This condition is often seen in hypertension and cerebral accidents.
2. Extreme Heat Causing Wind
This condition occurs most commonly in the advanced stage of heat diseases. As exuberant heat evil burns the body fluids, and the lack of nourishment injures the tendons and vessels, this leads to the superabundance of yang-heat which transforms into endogenous wind. The result is convulsions, spasms, nasal flaring, and upward staring 0f the eyes, accompanied by high fever, coma, and delirium. In general, this condition is primarily attributable to excess syndrome, which subsequently transforms into collapse syndrome.
3. Yin Deficiency Causing Wind
This condition usually appears in cases of impaired yin-fluid in the later stage of exogenous heat diseases, or in cases of severe consumption of yin-fluid due to prolonged illness. It belongs to the category of deficient wind stirring within. The main cause of its pathological mechanism is the exhaustion of yin-fluids, which creates a lack of nourishment of the tendons and vessels, and then brings on endogenous wind. It is marked by spasmodic tendons and muscular twitching, tremors of the hands and feet, and is accompanied by symptoms and signs of deficient heat.
4. Blood Deficiency Causing Wind
This condition occurs most commonly in cases of a lack of blood formation or a great loss of blood, or the impairment of the blood caused by prolonged illness. The lack of nourishment of the tendons and vessels or collaterals due to the insufficiency of the liver blood creates a syndrome of deficient wind stirring inside, characterized by numbness of the limbs and trunk, or spasmodic tendons and muscular twitching, or even rigid hand and feet.
Blood-dryness producing wind may be caused by a number of factors: the exhaustion
of yin and blood due to prolonged illness, deficient essence and blood due to aging, the lack of blood formation due to long-term malnutrition, or the disturbance of new blood formation due to internal congealment of the blood. Its pathological mechanism develop from the exhaustion of body fluids and blood, which then fail to nourish the muscles and skin and are transformed into endogenous dryness. This results in the disharmony of the meridians, qi and blood, and thus creates the condition. It is characterized by dry skin or dry scaly skin and itching.
II. Endogenous Cold
This phrase refers to a pathological state in which debilitation of yang-qi leads to the decrease of the warming and transformative functions, which then results in the inhibition or hypofunctioning of the physiological activities of the viscera and tissues. It often occurs in cases of yin exuberance due to debilitation of yang-qi, caused by an innate insufficiency, postnatal malnutrition, or an impairment of yang-qi due to prolonged illness. It is termed "deficient cold originating within," or, "endogenous cold. " Its pathologica mechanism is mainly manifested in the following two aspects:
First, yang deficiency leads to yin exuberance, while exuberant yin brings about endogenous cold. Yang-qi debilitation of the viscera and tissues produces the pathological reactions with the deficient cold properties. Thus, Chapter 39 in Plain Questions states: "The cold leads to the shrinking of qi. " For example, cold in the blood vessels causes the contraction of the blood vessels and retarded blood circulation; cold in the interstitial space between the skin and flesh leads to the shrinking of defense-qi and the closing of the interstitial space due to contraction of the sweat pores; and cold in the skin, tendons, and muscles gives rise to dysfunction of the warming function. Therefore, if the body's yang-heat is insufficient, it fails to perform its warming function for the blood vessels, muscles, and tendons, and a series of symptoms and signs of "constriction" may occur, such
as pallor, an aversion to cold, preference for warmth, lying with curled body, cold trunk and limbs, cold and clammy limbs, lack of perspiration, or cold pain in the local area.
The pathological changes of endogenous cold are closely related to yang deficiency of both the spleen and kidney. Kidney-yang (the vital gate fire) is considered to be the root of yang-qi of the body and has the function of warming the viscera, tissues, and organs.The spleen is the acquired foundation and the source of growth and transformation of qi and blood, and it is in charge of transportation and transformation, and it distributes the essential substances to nourish the viscera and tissues, thus allowing yang-qi to reach the four extremities. Yang deficiency of both the spleen and kidney thus leads to disturbance of yang-qi in its warming function, and is likely to present symptoms of deficient cold, among which deficient kidney-yang is particularly important. Thus, Chapter 74 in Plain
Questions states: "Cold syndromes characterized by contraction are related to the kidney."
Second, deficiency of yang-qi causes the decline of the transformative function of qi. The yang fails to transform yin, and the disturbance or hypofunctioning of the metabolic activities of the body leads to the accumulation or retention of pathological products that indieate yin-cold, creating the syndrome of water-dampness and phlegm-retention.Thus, Chapter 74 in Plain Questions states: "Disorders characterized by thin, clear, and watery discharge are related to the cold. " Its symptoms may include frequent urination with clear urine increased in volume, diluted and clear nasal discharge, saliva and sputum, diarrhea, or edema. Such a condition usually occurs when deficiency of yang-qi fails to evaporate and transforms the water-fluid into qi.
III. Damp-Turbidity Encumbered Within the Body
This phrase refers to a pathological state in which the hypofunctioning or disturbance of the spleen in its functions of transporting and transforming drink, food, and waterdampness, and of distributing the body fluids, leads to the imbalance of the metabo1ism of the essential substances of drink, food, and body fluids. The result is retention of water-dampness and accumulation of phlegm-turbidity within the body. Since dampness produced from within, it is also called "endogenous dampness. "
This condition may Occur most commonly in cases of deficient spleen due to prolonged illness, excessive phlegm-dampness, or in eases of internal injury of the spleen and stomach due to indulgence in raw and cold food, or when overeating fat and delicious food creates a weakness of spleen-yang or an impairment of spleen-qi. The spleen fails to perform its transporting and transforming functions, and is unable to convey the body fluids for the stomach. Thus, the distribution of water-fluid is impeded, resulting in water-fluid gathering to form fluid-retention, and accumulating to form water. Hence, the failure of the spleen in its transporting and transforming function is the key factor causing internal encumbrance of damp-turbidity, as described in Chapter 74 in Plain Questions"Dampness syndromes characterized by edema and fullness are related to the spleen."
The spleen's domination of transportation and transformation depends on the warm
ing and transformative function of kidney-yang. Therefore, endogenous damp-turbidity is not only a pathological product resulting from the failure of spleen-yang in transforrnin the body fluids, but also is closely related to the disturbance of the kidney's function Since the kidney is in charge of water-fluid, and kidney-yang is the foundation of a kinds of yang-qi, damp-turbidity usually occurs when impairment of kidney-yang affects the functions of the spleen in transporting and transforming. Conversely, since darnpness pertains to yin evil in nature, excessive dampness is prone to impair yang-qi. For this reason, a long-standing encumbrance of damp-turbidity would be certain to injure spleen-yang and kidney-yang, thus creating a syndrome of excessive dampness due to deficien
yang. Endogenous dampness caused by deficient kidney-yang also is usually related to the pathological changes of endogenous cold.
Dampness is characterized by heaviness and turbidity, viscosity, and stagnation, a is likely to block the functional activities of qi. The pathological changes of endogenous dampness mainly result from the obstruction of the functional activities of the upper-jiao middle-jiao, and lower-jiao. Its pathological reactions may vary depending upon the locations it blocks. If damp evil stagnates in the meridians, the result is fullness and heaviness of the head with a "bag-over-the head" sensation, and leaden and cumbersome limbs Thus, Chapter 74 in Plain Questions states: "Syndromes characterized by convulsion and stiff neck are related to dampness. " If damp evil invades the upper-jiao, chest distres and coughing occur; damp-obstruction in the middle-jiao leads to fullness and distension in the abdomen, poor appetite, sticky, bland or sweetish taste in the mouth, and a thick and slimy tongue coating; damp-stagnation in the lower-jiao creates abdominal distension, loose stools, and difficulty in urination. If water-dampness overflows into the interstitial space between the skin and flesh, edema may result. Thus, Chapter 71 in Plain Questions states: "Excessive dampness causes diarrhea, and even edema is due to waterobstruction. " However, it is necessary to point out that damp-obstruction of the spleen and stomach in the middle-jiao is considered to be the primary affected region. Hence,damp encumbrance due to deficient spleen is the syndrome that may be often observed.
In addition, although exogenous damp and endogenous damp are different in their
formation, they often influence each other. Endogenous damp evil is likely to invade the spleen. Failure of the spleen in transportation and transformation, in turn, leads to internal accumulation of damp-turbidity. In clinical practice, a person with failure of the spleen in transportation and transformation or excessive endogenous dampness is shsceptib1e to exogenous damp evil.
IV. Impairment of Body Fluids Transformed into Dryness
This phrase points to a pathological state in which an insufficiency of body fluids leads to a lack of nourishment and moisture of the tissues, organs, and orifices of the body, producing dryness and exhaustion of the body fluid. It is thus called "endogenous dryness. " It may occur most commonly in cases of depletion of body fluids caused by prolonged illness, by profuse sweating, vomiting, or diarrhea, by exhaustion of yin-fluid due to 10ss of blood and essence, and by damage to yin due to heat evil or transformation of damp evil into dryness in the course of certain febrile diseases. Since deficient body fluid is ruble to nourish the viscera internally and moisten the interstitial space between the skin and flesh and the orifices externally, there will be endogenous dryness, marked by pathological changes of dryness. Thus, Chapter 5 in Plain Questions states: "Predominance of dryness brings about aridity. "
Generally, damage to yin-fluid may give rise to "endogenous dryness," while consumption of the body fluids caused by excess-heat may lead to endogenous dryness-heat. Therefore, this pathological change may occur in various viscera, tissues, and organs, but most commonly is seen in the lung, stomach, large intestine, and kidney. When lung-yin is insufficient, the lung fails to perform its dispersing and distributing functions,and the dryness may appear. Conversely, exogenous heat evil easily damages lung-yin, and there may appear the scorched lung with impairment of the body fluids, and the synrome of dryness-heat due to deficient yin results. The symptoms are dry cough without sputum, or sputum mixed with blood, or hemoptysis.
Accumulation of excess-heat in the stomach and intestine is likely to damage the body fluids, and impairment of the body fluids creates the dry syndrome, marked by constipation,
The kidney stores the essence, and kidney-yin is the foundation of yin-fluid of the five zang-viscera. For this reason, deficient kidney-yin, and impairment of the essence may also be transformed into dryness, thus, creating the syndrome of endogenous due to deficient yin, a condition of hyperactivity of the vital gate fire. This leads to fever from steaming bone, and sexual hyperfunction.
In addition, traditional Chinese medicine believes that the body fluids and blood an derived from the same source. Depletion of body fluids leads to blood-dryness, and the lack of nourishment of the tendons and bones may bring on weakness of joint movemer and spasm.
The pathological changes of endogenous dryness are marked by manifestations due
depletion of the body fluids, with such symptoms as rough and dry skin, scaling skin
chapped mucous, dry mouth and throat, dry tongue with no little liquid, bright red and cracked tongue, dry nostrils and eyes, brittle nails, constipation, dark scant urine,cough with no sputum, or even sputum mixed with blood. Thus, physician Liu Wansu described this in his work, Etiology Based on Plain Questions: "Syndromes characterize by depletion of the body fluids, and scaling and chapped skin, are related to dryness Deficient yin and damaged fluid also may create endogenous dryness-heat. The symptom may include hot sensation in the palms and soles, vexation, insomnia, and rapid thready.
V. Endogenous Fire-Heat
This condition is also known as "endogenous heat" or "endogenous fire. " It refers to a pathological state in which an internal disturbance of fire-heat and hyperfunctioning the body are caused by exuberant yang or hyperactivity of yang due to deficient yin, or by the stagnation of qi and blood, or the accumulation of pathogenic evils.
The fire and heat are of the same sort and both pertain to yang. Thus, there is saying that "fire is intense heat and heat is mild fire. " For this reason, they are almost the same in their pathological mechanisms and clinical manifestations. However, each different in its degree. Endogenous fire-heat is divided into deficiency and excess patterns in its formation. The types of pathological mechanisms may be summarized as follows:
¢Ù Exuberance of yang transforming into fire: Under normal physiological conditions, yang-qi in the human body has a role in nourishing the vitality, softening tendons and warming the viscera and tissues. It is termed "junior fire" in traditional Chiness medicine, but, under a pathological condition, exuberance of yang-qi and hyperfunctioning of the body create the increase of material consumption, and result in the impairrnen of yin-fluid. This pathological exuberance of yang-qi is thus called "sthenic fire," and also known as "the hyperfunctioning of qi may lead to fire" in traditional Chinese medicine.
¢ÚDepression of pathogenic evil transforming into fire: This term includes two types of pathological mechanisms: The exogenous six climatic evils, such as wind, cold, dryness, dampness, etc. , can be all transformed into heat or fire along with a yang constitution in the course of disease, e. g. , the transformation of stagnant cold into heat, of stagnant dampness into fire, and so on. On the other hand, the term also includes the pathological metabolic products in the body, such as phlegm-retention, blood stasis, retention of food and parasitic infectionk etc. which can be transformed into fire. The main pathological mechanism of this condition stems from stagnant yang-qi due to the pathogenic factors, which is then transformed into heat or fire.
¢ÛTransformation of extreme five emotions into fire: This is also called "five emotional fire. " It usually occurs when mental and emotional irritation disturbs the physiological balance bet,been yin and yang, qi and blood, zang-viscera and fu-viscera, and the result is blocking of the functional activities of qi. Long-standing depression of qi may turn into heat in a patient with a yang constitution. This is a reason that fire-heat originates within. For example, internal injury from mental depression often leads to stagnation of liver-qi, which as mentioned above, is mostly attributable to the syndrome of excess-fire.
¢Ü Flaring of fire due to yin deficiency: This condition belongs to deficient fire. It usually occurs in cases of yin deficiency due to hyperactivity of yang caused by the impairment of the essence and blood or the heavy consumption of yin-fluid. In general, systemic deficient heat signs are most commonly seen in the syndrome of endogenous heat due to deficient yin. However, the symptoms and signs of fire-heat that indicate flaring of fire due to yin deficiency are usually centered in a certain area of the body, such as a toothache, sore throat, dry mouth and lips, steaming bone syndrome, or malar flush. All of these are caused by flaming up of deficiency-fire.
In addition, the visceral fire is often caused by an imbalance between zang-viscera and fu-viscera, yin, and yang. (See the section on pathological mechanisms of the viscera.)
