The Six Climatic Evils
CHAPTER FIVE ETIOLOGY AND PATHOGENESIS
TCM holds that there are both opposite and unitary relationships between the viscera and tissues, and between the human body and the natural environment. These things maintain a relative dynamic balance through a process in which contradiction alternately appears and disappears, in order to sustain the normal physiological activity of the human body. When this dynamic balance is broken for some reason and can not immediately be restored through self-regulation, certain diseases will occur.
The pathogenic influences breaking up the state of relative balance in the body and leading to diseases are called etiological factors. There are various kinds of etiological factors, such as climatic abnormality, spreading of infectious diseases, improper diet, overstrain, overexertion from bearing weight, external injuries by tripping and falling,wounds by sharp metallic objects, animal or insect bites, etc. Moreover, in the develop mental process of disease, the cause and result of disease interact. That is to say, the consequence of disease at one pathological stage may become an etiological factor at another stage. For instance, the phlegm and stagnant fluid, and blood stasis, on the one hand,are the pathologic products of the dysfunction of qi, blood and the viscera. Subsequently,they may become the etiological factors of other diseases.
Section 1 Etiology
The etiological factors that cause the occurrence of disease are varied, and these factors may lead to diseases under certain conditions. The ancient Chinese doctors classified the etiological factors in different ways in order to explain their properties and manners for causing diseases. For example, in The Yellow Emperor's Internal Classic, all the etiological factors were classified into two categories for the first time, namely yin and yang. Chapter 62 in Plain Questions points out: "The pathogenic evils either originate in yin or originate in yang; those coming from yang are related tO wind, rain, cold, and heat; those coming from yin are related to food and drink, living places, sexual life, and emotions such as joy and anger. " In his book entitled Synopsis of Prescriptions of the Golden Chamber, Dr. Zhang Zhongjing of the Han Dynasty said that all diseases were caused by the evils in three ways: "All diseases and medical problems are exactly within three categories: ¢Ù the meridians are first attacked by the evils, then the viscera are affected ; and there is an endogenous cause for this ; ¢Ú the vessels and blood circulation that maintain and connect the four limbs and the nine body orifices are blocked, and this is caused by the evils attacking the skin externally; and ¢Û there are medical problems related to the factors such as sexual activities, injuries by sharp metal things, bites by insect or beast. From this point of view, it can be said that all the etiological causes are included here. "Dr. Tao Hongjing of the Jin Dynasty, in his book entitled A Pocketbook of 100 Recipes, divided all etiological causes into "the endogenous, the exogenous, and others. " Dr. Chen Wuze, of the Song Dynasty, extended Dr. Zhang Zhongjing's idea of that "all diseases and medical problems are exactly within three categories," and put forward his "three-factors theory," saying: "The six climatic evils are related to the natural climatic changes; when they overact, they first get into the meridians and collaterals, then into the viscera, so they are exogenous etiological factors. The seven emotions are natural feelings of the human beings; when they arise up, they first affect the viscera, then the exterior of the body, so they are endogenous etiological factors. The others, like hunger,overeating, impairment of qi by yelling, traumatic injuries by metal things, incomplete fracture, infectious pathogens, evil spirit, fright, crushing, drowning, etc. , are all beyond the natural scope, so they are neither endogenous nor exogenous factors. " It can be seen that the method used by ancient Chinese physicians to classify etiological factors according to their ways of causing disease possesses a guiding significance for clinical syndrome differentiation.
According to TCM, there is no symptom without any cause, and any kind of symptoms certainly is a reflection of the body being affected and influenced by some pathogenic factors. To understand the causes of diseases, TCM examines the clinical manifestations of diseases and studies the possible pathogenic factors. The procedure of finding the cause of disease through an analysis of the symptoms and clinical signs is termed "finding the cause of disease by syndrome differentiation. " The TCM etiology, therefore, studies not only the properties and pathogenic characteristics of etiological factors, but also the clinical manifestations of the syndromes and diseases caused by various etiological factors, in order to direct clinical diagnosis and treatment.
I. The Six Climatic Evils
The six climatic evils include wind, cold, summer-heat, dampness, dryness and fire. These are normally called "the six climatic factors," i.e. the six natural climatic variations. The six climatic factors represent the natural conditions within which all living things exist, and they do people no harm. Chapter 25 in Plain Questions says: "People live on what is produced by the sky and earth, and grow and develop according to the law of the seasons. " In other words, human beings depend on the air and nutrient essence existing between the sky and the earth, and live, grow, and develop in accordance with the seasonal law of germinating, growing, and maturing. Moreover, human beings have learned how to deal with the seasonal changes through their living experiences and obtained certain adaptive abilities, so the six natural climatic factors generally can not cause people to suffer from disease. But the climate may become a pathogenic factor under lira ited circumstances; for example, when climates change abnormally, i.e. the energetic levels of the six climatic factors become too high or too low and do not correspond to their respective season (for example, an abnormally cool spring, or an abnormally warm autumn), or when climates change wildly. Then they will invade the human body and cause diseases if the body's energetic level of genuine-qi is low, and if its ability to resis
disease is weak. Only under these circumstances are the six climatic factors termed "the six climatic evils. " (They are also termed the "six yin. " The Chinese word "yin" heft means overacting, penetrating and dispersing. ) The six climatic evils belong to the category of exogenous pathogenic factors.
The six climatic evils have the following pathogenic features.
(1) The diseases caused by the six climatic evils are mostly related with seasons and living or working environments. For example, generally, there are wind diseases in spring, summer-heat diseases in summer, damp diseases in late summer and early autumn, dry diseases in autumn and cold diseases in winter. In addition, "people who live for an extended period of time in a damp environment tend to be easily attacked by the damp evil, and those who work long in an environment of high temperature tend to be easily attackect by the dry-heat evil or fire evil.
(2) All of the six evils can act either alone or in a combination of two or more in attacking the human body. Such syndromes as common cold of wind-cold type, damp-heat diarrhea, wind-cold-damp blockage, etc. , are examples of medical problems caused by the composite evils.
(3) In the course of causing diseases, any one of the six climatic evils not only can be influenced by the others, but also can be transformed into another kind of evil under certain conditions. For example, the cold evil that enters the interior of the body can be transformed into the heat evil, and the long-persisting summer-heat with dampness can be transformed into dryness, causing yin consumption.
(4) In most cases, the six climatic evils get into the body and cause diseases through the skin and muscle, or the mouth and nose, or through both ways; so they are also termed "the six exogenous evils. "
In today's clinical practice, the syndromes and diseases cauged by the six climatic evils also include the pathological problems produced by biological factors (bacteria,virus, etc. ), chemical factors, and so on. At a minimum, TCM's study of the cause and course of disease should take all the exogenous etiological factors which can be classified according to the clinical manifestation of the six climatic evils, and the body's pathological responses to them, into consideration. Although this concept needs refining, it is an acceptable beginning approach.
Besides the exogenous syndromes caused by the six climatic evils, there also are syndromes caused by the transformed wind, transformed cold, transformed dampness,transformed dryness, transformed heat, and transformed fire produced by the viscera when in dysfunction. Although their clinical manifestation is similar to that of the syndromes caused by the six climatic evils, they are not caused by the exogenous evils. In order to differentiate between the two categories of syndromes, the transformed evils by the viscera in dysfunction are called "the five endogenous evils," i.e. endogenous wind, endogenous cold, endogenous dampness, endogenous dryness, and endogenous fire (or heat). The pathological effects of these transformed endogenous evils will be introduced later in a section entitled "The Five Endogenous Evils. "
1. Wind
Although it exists in all seasons, wind is the main factor in spring. Diseases caused by the wind evil could occur in any season, but are predominant in spring. The wind evil is considered by TCM to be the most important factor causing exogenous diseases.
The wind evil gets into the body mainly via the skin and the interstitial space of the flesh. It produces exogenous syndromes, as Chapter 42 in Plain Questions says: "The wind evil can hide in the skin. It causes the symptom of cold when the interstitial space opens, and causes the symptoms of heat and choking when the interstitial space texture doses. "
The characteristics and pathogenic features of wind are as follows:
(1) The wind evil possesses a penetrating ability, and pertains to the yang evils. It is likely to invade the yang sites of the body. The wind evil is active and motional, and is characterized by its ascending, pervading, and going upwards and outward, thus it pertains to the yang evils. The penetrating ability of the wind evil refers to the fact that the wind evil can loosen the skin and interstitial space of flesh and pervade them. These characteristics make the wind evil more likely to attack the upper part of the body (i. e. the head and face), yang meridians, and the skin and muscle. It produces symptoms such as headache, sweating, and aversion to wind. Chapter 29 in Plain Questions says:
when the wind evil attacks, the yang parts of the body first suffer," and "When the wind evil invades, the upper part of the body first suffers. "
(2) The wind evil is movable and changeable. To say that the wind evil is movable refers to the fact that the diseases caused by the wind evil are characterized by their movable sites. For example, if the blockage syndromes caused by wind-cold-damp manifests migrating arthralgia, wind must play a main role in the syndrome, and it may be termed "migrating blockage" or "wind blockage" in this case. To say that the wind evil changeable refers to the fact that the diseases produced by it are characterized by their quick onset and irregular changes. For example, with wind-rash the itching of the skin causes the condition to rise and subside irregularly in one area after another. Chapter 42 in Plain Questions says: "Wind wanders and changes quickly.
(3) The wind is the leading evil of all diseases. Other evils such as cold, dampness,dryness and heat, attach themselves to wind in most eases when they launch invasions against the human body. For example, there are exogenous syndromes of wind-cold,wind-heat, wind-damp, etc. So, it can be said that the wind evil plays a leading role in producing exogenous syndromes; and the ancient Chinese physicians even named all the exogenous evils after wind, just as is stated in Chapter 60 in Plain Questions: "Wind is the origins of all diseases," and "Wind is the primary evil of all diseases. "
2. Cold
Cold is the main factor in winter. When people live in a cold winter or suffer from sudden sharp decrease of the environmental temperature, they are susceptible to attack by the cold evil if they do not protect themselves. In addition, being caught in the rain,wading, and being exposed to the wind when sweating, all are important contributint factors to being attacked by the cold evil.
The syndromes caused by the cold evil can be divided into two kinds--the exogenous cold syndrome and endogenous cold syndrome. The exogenous cold syndrome refers to the syndrome produced by the cold evil attacking the human body from the exterior, and it can further divided into "the cold-attack," caused by the cold evil attacking the exterior of the body and suppressing the defensive yang-qi, and "the interior cold-attack," caused by the cold evil attacking the interior of the body and impairing the visceral yang-qi. The second category of syndrome, the endogenous cold syndrome, is the pathological response of the body to the shortage of yang-qi and the lack of the warming of yang-qi. The two kinds of cold syndromes are interrelated, although there is a difference between them.For example, the body in a state of yang deficiency and internal cold tends to suffer from the attack of exogenous cold, while the exogenous cold that persists in the body without dispersing may impair the yang-qi and leads to endogenous cold syndrome.
The cold evil has the following characteristics and pathogenic features:
(1) Being a yin evil, cold tends to impair yang-qi. Cold pertains to the yin category because it is the manifestation of the yin-qi. Chapter 5 in Plain Questions says: "The predominance of yin results in cold. " The yang-qi normally can restrain yin, but when yin-cold becomes predominant, the yang-qi not only fails to dispel the yin-cold evil, but also suffers from the over-action of the yin-cold. Chapter 5 also says: "The predominance of yin results in the disorder of yang. " Thus, on being affected by the cold evil, the yang-qi of the body is most easily impaired. The cold syndrome resulting from the declined yang-qi will appear when the yang-qi is impaired. For example, when exogenous cold invades the skin and muscle and the defensive yang is checked, the symptom of aversion to coldness will appear; when the cold evil directly attacks the spleen and stomach and the spleen-yang is impaired, symptoms such as cold pain in the abdomen, vomiting,and diarrhea will occur; and when the cold evil directly attacks the Shaoyin Meridians when both the heart-yang and kidney-yang both are deficient, symptoms such as aversion to coldness, lying huddled, cold hands and feet, diarrhea with undigested food in the stool, large amount of clear urine, despondence, and weak and thready pulse will appear.
(2) It is the nature of cold to congeal and to stagnate. Smooth circulation of qi, blood, and body fluid depend on the warming function and motive force of the harmonious yang-qi. Onee the yin-cold evil becomes predominant and impairs the yang-qi, the consequence will be as is described in Chapter 39 in Plain Questiens:"The cold evil enters the meridians, causing the circulation of qi and blood to become slow and unsmoothed,goes outside the vessels, leading to a decrease in blood volume, and goes inside the vessels, clogging the flow of qi and blood, and causing sudden pain. " In other words, the circulation of qi and blood will become slow, unsmoothed and stagnated if the qi and blood inside meridians and the vessels are congealed and obstructed by the cold evil. The congealment and obstruction of qi and blood result in pain, so the symptom of pain will often come out when the body is attacked by the cold evil. Chapter 43 says- "Pain is caused by the overacting of cold, and cold produces pain. " So, it is said that cold, which is characterized by stagnation and coagulation, is responsible for pain.
(3) It is the nature of cold to contract and to shrink. When the body being attacked by the cold evil, the function of qi is restrained, and the interstitial space, meridians, collaterals, tendons and vessels are contracted or spasmodic. Chapter 39 in Plain Questiens says. "Cold restrains the action of qi. " and "When the cold evil stays outside the vessels, the vessels will become constricted and spasmodic; and the small collaterals around them will become tense, which can result in sudden pain. " If the cold evil attacks the skin and muscle so that the pores and the interstitial space are closed, with the defensive yang being restrained and failing to disperse, symptoms such as aversion to cold, fever and anhidrosis will if the cold evil invades the blood vessels and causes the stagnation of qi and blood, and contraction of the blood vessels, symptoms such as headache, pain all over the body and tense pulse will appear; and if the cold evil attacks meridians, collaterals, and joints, and causes tenseness and constrict of the meridians and blood vessels, the limbs will fail to bend and stretch freely, or become cold and numb.
3.Summer-Heat
Summer-heat originated in fire and heat is the main factor in summer time, so Chapter 67 in Plain Questions says: "The thermal energy (originating in the south) is called heat when existing in the heaven, and called fire when existing on the earth It has the nature of the heat of summer. " Diseases caused by summer-heat are obviously seasonal by nature, and mainly occur in a period following the Summer Solstice to before the Be ginning of Autumn, as is stated in Chapter 31: "The disease caused by the heat before the Summer Solstice is called warm disease, while the disease caused by the heat after the Summer Solstice is called summer-heat disease. " Summer-heat is an exogenous evil only,and there is no endogenous summer-heat evil.
The characteristics and pathogenic features of the summer-heat are as follows.
(1) The summer-heat belongs to the yang evils; and it is hot by nature. Summerheat is formed from the fire and heat in summer time, and it is categorized as a yang evil,for fire and heat belong to the yang category by nature. When the summer-heat evil attacks the human body, a series of yang-heat symptoms such as sthenic fever, dysphoria,flushed face, and a forceful and full pulse, will appear.
(2) The summer-heat evil is characterized by its ascending and dispersing activity,and it can consume qi and impair body fluid. Since summer-heat is a yang evil and yang tends to ascend and disperse by nature, this pathogenic factor mostly invades the human's qi system directly, and makes the interstitial space open and loose, with the consequence of over sweating. Over sweating causes, in turn, over consumption and insufficiency of body fluid, with the result that certain symptoms appear, such as thirst with a desire to drink, and short urinary flow. The summer-heat evil also disturbs the mind and causes dysphoria and restlessness. When the body is over sweating, as often happens, qi will escape with the loss of body fluid; then qi deficiency syndrome will arise. Therefore, the patient being attacked by summer-heat often presents the symptoms of short breath,tiredness, or even sudden unconsciousness. As is stated in Chapter 39 in Plain Questions; "Heat makes the interstitial space open and loose, the nourishing and defensive systems uncontrolled, and the body over-sweated, which causes qi to escape. " Chapter 71 also says: "When blazing heat is in action, the hottest days begin ... So the people suffer from short breath ... even dizziness, a sensation of choking in the chest, very uneasy stomach, and possibly even sudden death. "
(3) The summer-heat evil often mingles with pathogenic dampness. The summer
time, besides being very hot, is rainy and damp with the increased air humidity; and this is why the summer-heat evil often mingles with the damp evil on invading the human body. In this case, not only those symptoms caused by summer-heat, such as fever and dysphoria, appear, but they are accompanied by symptoms caused by damp-retention, such as tired limbs, a sensation of choking in the chest, and uncomfortable defecation with liquid stool.
4. Dampness
Dampness is the main climatic factor of the late summer. The late summer is the dampest period of the year, as the summer starts to change into autumn and the intensity of yang-heat decreases, with fogs and mists everywhere, vapor ascending, and dampness prevailing. The diseases caused by the damp evil can also be divided into exogenous syndromes and endogenous syndromes. The exogenous syndrome often appears when the human body is attacked by exogenous damp evil, which is related with the wet weather,wading, rain, and a damp environment. The endogenous syndrome is nothing but a pathological state due to failure of the spleen's transporting function. Although there is a difference between the exogenous dampness and endogenous dampness, the two kinds of damp evils often influence each other in the course of causing disease. For example, if the body is attacked by exogenous damp evil, the spleen will be distressed and fail to perform its transporting function, which leads to the endogenous damp syndrome; if the spleenyang is deficient or impaired and water-damp can not be dispersed, the exogenous damp evil will invade the human body easily.
The characteristics and pathogenic features of the damp evil are as follows:
(1) The damp evil is related with heaviness and turbidness. The heaviness refers to the patient's feeling as if he were bearing a heavy load, and is manifested in such symptoms as a sensation of heaviness in the head, feeling heavy and tired all over the body, and sluggish or heavy limbs. Chapter 3 in Plain Questions says: "The sensation of the head being tightly wrapped up is due to dampness. " It can be interpreted that the invasion of the skin and muscle by the damp evil causes the inhibition of the ascending of the lucid yang, and the disturbance of the harmony between the nourishing qi and defensive qi, which leads to dizziness and a sensation as if the head being wrapped up with a band of cloth. If the damp evil stays in the meridians and joints, the dispersal of the yang-qi will be disturbed, and symptoms such as numb and insensitive skin and muscle,and arthrodynia with a sluggish sensation, will appear, symptoms to which the term damp blockage" or "turbid blockage" is given.
The "turbidness" means a state of being turbid and dirty, and is often related with the turbid and dirty things secreted from the body. Diseases caused by the damp evil can show various symptoms concerning turbid and dirty secretions such as dirty appearance of the face with much gum from the eyes, liquid stools, dysentery, turbid urine, leukorrhagia. and ulcerative eczematosis all of which are pathological phenomena related to the turbid and dirty nature of the damp evil.
(2) The damp evil belongs to the yin evil, and it tends to disturb the functional activities of qi and injure the yang-qi. Being heavy and turbid by nature, the damp evil something like the water evil; so it belongs to the yin evil. On invading the human body the damp evil tends to stay in the viscera and meridians, which is most liable to distur the function activities of qi, causing abnormal ascending and descending of qi, and obstruction of meridians. This frequently produces a feeling of oppression in the chest and upper abdomen, scanty urine and difficult urination, uncomfortable defecation, etc Since damp evil belongs to yin evil and yang will be disturbed if yin becomes pred0rni nant, damp evil is most liable to impair the yang-qi when invading the human body. The spleen, categorized as yin-earth according to the yin-yang and five elements theories, the main zang-viscus in charge of the transportation and transformation of water-damp it functions normally in dry circumstances and abnormally in damp circumstances. When exogenous damp evil stays in the body, it often fetters the spleen first, causing inactive spleen-yang, failure of the physiological transporting and transforming, and water-damp retention, which produces diarrhea, scanty urine, edema, ascites, etc. So Chapter 71 in Plain Questions says: "When dampness becomes predominant, diarrhea with stick' stools will occur, and edema due to water-retention will appear. "
(3) Dampness is characterized by stickiness and stagnancy. The stickiness and stag nancy of the damp evil can be explained in two ways. First, the symptoms of damp diseases often have the nature of stickiness, e.g. sticky dejecta and secretions. Secondly damp diseases are often difficult to cure due to their long course and frequent recurrence e.g. such conditions as damp-blockage, eczema and damp-warm disease.
(4) Dampness tends to descend and attack the yin-site of the body. Diseases caused by the damp evil often produce the symptoms concerning the lower part of the body; for example, in the case of edema, leg swelling might be seen. In addition, symptoms such as stranguria with turbid urine, leukorrhea, diarrhea, and dysentery are mainly caused by the descent of the damp evil. For this reason, Chapter 29 in Plain Questions says "When the body is attacked by dampness, the lower part of the body will be first affected. "
5. Dryness
Dryness is the main climatic factor of autumn. In autumn, the weather becomes cool and dry because the air is astringent and there is a shortage of moisture. The dryness evil most frequently takes the mouth and nose as its pathways to attack the defensive system of the lung. Diseases caused by the dryness evil can be divided into two categories; the warm dryness syndrome and cool dryness syndrome. Since there the remains of summer heat exist in the early autumn, dryness can attack the human body together with warmheat, causing the warm-dryness syndrome; on the other hand, since the cold of the coming winter exists in the late autumn, dryness can attack the human body together with cold evil, causing the cool-dryness syndrome.
The characteristics and pathogenic features of the dryness evil are as follows:
(1) Dryness has a nature of drying and puckering, and tends to impair the body fluid. With a nature of drying and puckering, dryness evil is most likely to impair and consume the body fluid, producing the syndrome of insufficiency of both yin and body fluid, and producing such symptoms as dry mouth and nose, dry throat, thirst, dry and rough or chapped skin, malnourished hair, or scanty urine and constipation. As is said in Chapter 5 in Plain Questions: "There will be aridness when dryness becomes predominant. "
(2) Dryness tends to impair the lung. The lung is a "delcate organ" which functions normally when being moistened, and functions abnormally when being affected by dryness. The lung predominates qi, controls respiration and is open towards the outside air;so Chapter 6 in Plain Questions says: "The qi of heaven is in communication with the lung. " Again, the lung is related to the skin's fine hairs and the skin itself, and has the nose as its outside orifice. Attacking the human body via the mouth and nose, dryness is most likely to consume the lung-fluid and impair the dispersing and leading downwards functions of the lung, producing asthma, pectoralgia, or dry cough with phlegm in small amounts, or with sticky phlegm, or with phlegm mingling with blood.
6. Fire (Heat)
Fire comes into being when yang becomes predominant. Fire includes warm and
heat. Heat is the extreme of warm, and fire is the extreme of heat. Heat mainly acts as an exogenous evil existing in different forms; for example, wind-heat, summer-heat and damp-heat, while fire mostly acts as an endogenous evil causing many kinds of syndromes, such as flaming up of the heart-fire, ascending of the liver-fire, and running wild of the gallbladder-fire.
The syndromes caused by fire and heat can also be divided into exogenous and endogenous. The exogenous is primarily produced by the direct invasion of warm-heat
evils, and the endogenous is mainly due to the failure of the coordination of zang-viscera and fu-viscera, yin and yang, qi and blood, and to the predominating of the yang-qi.Chapter 62 in Plain Questions says: "The endogenous heat comes into being when yin becomes deficient; the exogenous heat comes into being when yang becomes predominant. " Dr. Zhu Danxi also said, "Fire comes from an excess of qi. " In addition, wind, cold, summer-heat, dampness, dryness, or emotional stimulation coming from a condition where "the five emotions become extreme," all can produce fire, from which comes out the terms "fire-transformation of the five climatic factors" and "fire-transformation of the five emotions. "
The characteristics and pathogenic features of the fire-heat evil are as follows: .
(1) Pathogenic fire-heat is one of the yang evils and it flames upwards. Chapter 5 in Plain Questions says: "Heat will come into being when yang becomes predominant."
Yang is characterized by restlessness and upwardness; so fire-heat belongs to yang evils since it "burns and flames" upwards. On attacking the human body, therefore, fire-heat mostly produces high fever, aversion to heat, thirst with restlessness, sweating, a full and rapid pulse, etc. When flaming upwards and disturbing the mind, this yang evil often produces vexation and insomnia, mental disarrangement and wild behavior, coma, delirium, and so on. Chapter 74 in Plain Questions says: "All the symptoms characterized by restlessness and mania are related to fire. " In clinical practice, it can be seen that the syndromes caused by fire-heat are mostly related with the upper part of the human body, for example, the head and face.
(2) Fire is likely to consume qi and impair the body fluid. The fire-heat evil is most likely to drive the body fluid out and to heat the yin-fluid, and leads to the consumption and impairment of the yin-fluid. The diseases caused by the fire-heat evil often produce thirst with desire for drinking, dry mouth, scanty urine in dark color, constipation,etc. , which are related to the consumption and impairment of the body fluid. Chapter in Plain Questions points out: "Sthenic fire eats qi. " The sthenic fire refers to the excessive fire caused by hyperactive yang-heat, which is most likely to impair the genuine-qi,causing general loss of the body fluid and qi.
(3) Fire may produce wind and stir up the blood. When fire-heat evil invades the human body, it will often heat the liver meridian and consume the yin-fluid; as a result,the tendons and vessels can not be nourished and moistened; and the syndrome of stir ring-up of the liver-wind can appear, of which it is Said, "The extreme of heat produces wind. " In such a case, there will be symptoms like high fever, coma, delirium, convulsion, upwards staring, stiff neck, and opisthotonos. So Chapter 74 in Plain Questions says: "Heat syndromes characterized by fainting and convulsion are related to fire. " The fire-heat evil, at the same time, can speed up the blood flow and damage the blood vessels by heating them, and in critical cases, it can make the blood go out of its course, which leads to various kinds of bleeding such as hematemesis, nosebleed, stool with blood, urine
with blood, purpura, profuse menstruation, metrorrhagia and metrostaxis.
(4) Fire is likely to cause sores and ulcers. On attacking the blood phase of the body, the fire-heat evil can stagnate at a particular site and erode the blood and flesh there, thus leading to sores and ulcers. Chapter 81 in Spirit Pivot says: "When high fever persists and becomes predominant, the flesh will erode and produce pus, which is termed carbuncle." Chapter 74 in Plain Questions also says: "All kinds of painful and itchy sores are related to the heart," which means that all kinds of painful and itchy sores are caused by the fire-heat in the heart meridian. The Golden Mirror of Medicine also speaks on this subject. It says: "Carbuncles and gangrene are caused by the poisonous fire. " In clinical practice, swollen sores and ulcers with a local fever are differentiated as yang and fire-problems.
In addition, it is held that fire and heat are related to the heart, which dominates the blood vessels and stores the mind. When it becomes predominant, fire can cause disturbance of the heart, producing symptoms of mental restlessness, dysphoria, delirium, wild behavior, coma, in addition to the syndromes with symptoms related to the heat in the blood and stirring-up of the blood.
