Issues and Solutions in the Theory of Exogenous Pathogenic FactorsXiao Xiangru, Dong ZhengpingThe theory of exogenous pathogenic factors in TCM includes the “Six Excesses” and the concept of miscellaneous qi (epidemic qi, pestilential qi). Among the “Six Excesses”, “Wind” often refers broadly to external pathogens rather than specific causes; “Fire” cannot be an exogenous factor; and the essence of “Summer Heat” is “Heat”.The theory of “Miscellaneous Qi” cannot guide the clinical treatment of exogenous diseases.It is evident that the current theory of exogenous pathogenic factors has issues that require research and standardization.1. Issues in the Theory of the “Six Excesses”In the “Su Wen: Treatise on the True Essentials”, it states:“All diseases arise from Wind, Cold, Summer Heat, Dampness, Dryness, and Fire, which transform and change.”It is generally believed that the concept of the “Six Excesses” originates from this. Thus, for a long time, the exogenous pathogenic factors in TCM have been referred to as the six evils: Wind, Cold, Summer Heat, Dampness, Dryness, and Fire.However, there are issues with the theory of the “Six Excesses”.(1) “Fire Evil” is not an exogenous evilThere is considerable debate regarding whether Fire Evil belongs to the Six Excesses. In 1979, Li Jinyong[1] examined the original texts of the “Nei Jing” and concluded that the original text only included the five evils corresponding to the seasons: “Wind, Summer Heat, Dampness, Dryness, and Cold”. The addition of “Fire” to make it “Six Excesses” originated from the “Seven Treatises on Qi” written during the Eastern Han Dynasty.The purpose was to align the “Qi Theory” with the need for the “Three Yin and Three Yang” in the six seasonal qi. In 1981, Wang Yuanshi[2] pointed out that “Fire” only exists in physiological and pathological forms, and there is no exogenous fire, thus it cannot be listed alongside the other five evils.The term “Six Excesses” first appeared in the Song Dynasty in Chen Wuze’s “Treatise on the Three Causes and One Disease”[3]: “The Six Excesses are the common atmospheric evils; if encountered, they first enter the meridians and then affect the organs, causing external diseases.” Chen noted that “the Six Excesses are Cold, Summer Heat, Dryness, Dampness, Wind, and Heat.” Based on this understanding, “Fire” among the Six Excesses should be changed to “Heat”.(2) The essence of Summer Heat is HeatAccording to Li Jinyong’s examination of the character “暑” (Summer Heat)[1], the original meaning of “暑” is “Heat”. However, from clinical practice, “Summer Heat” is a specific manifestation of Heat.First, it is believed that there is seasonality, meaning “the heat before the summer solstice is called Warmth, and after the summer solstice, it is called Summer Heat”; only the heat in summer is called Summer Heat.Second, Summer Heat is more intense than heat at other times, hence the term “scorching summer heat”. In clinical terms, general heat initially affects the lungs, known as “Warm Evil first affects the lungs”, presenting as symptoms of Yin Qiao San or Sang Ju Yin; whereas Summer Heat initially affects the Yangming, referred to as “Summer Heat arises from Yangming”, presenting as symptoms of Bai Hu Tang.Third, Summer Heat often carries Dampness. In summer, due to the hot weather, the evaporation of surface water increases the humidity in the air, creating a damp and hot environment, which often leads to diseases characterized by both Heat and Dampness, hence it is sometimes referred to as “Summer Heat with Dampness”.Regardless of its specificity, the essence of its heat remains unchanged, therefore in the current theory of the Six Excesses, “Summer Heat” is essentially “Heat” and does not need to be listed separately.(3) “Wind” is not a specific pathogenic causeAmong the Six Excesses, “Wind” appears most frequently in the “Huangdi Neijing”; there is even a dedicated chapter on “Wind” in the “Neijing”.In this chapter alone, diseases caused by Wind Evil include Cold Heat, Heat in the Middle, Cold in the Middle, Pestilential Wind, Partial Paralysis, Liver Wind, Heart Wind, Spleen Wind, Lung Wind, Kidney Wind, Partial Wind, Eye Wind, Leaky Wind, Internal Wind, Head Wind, Vomiting Wind, Stomach Wind, etc. From the characteristics of these symptoms, there are both exogenous and internal injuries.It is evident that in the “Neijing”, the connotation of “Wind” Evil has an infinite tendency to generalization, which leads to confusion in both theoretical and clinical applications, even resulting in disputes over the Yin, Yang, Cold, and Heat attributes of Wind Evil[4] [5] I believe that “Wind Evil” is not an independent pathogenic cause.1. “Wind Evil” generally refers to external evilsIn the “Neijing”, “Wind Evil” often refers to all exogenous pathogenic evils, as seen in the “Su Wen: Treatise on the Ancient Heavenly Truth” stating “the virtual evil of the Wind should be avoided at certain times” and in the “Su Wen: Treatise on the Correspondence of Yin and Yang” stating “when the evil Wind arrives, it is as swift as wind and rain”, as well as in the “Ling Shu: Five Transformations” stating “when encountering Wind at one time, the diseases vary”, all of which refer to all exogenous pathogenic evils rather than specific causes.The textbook of TCM Internal Medicine states[6] that the cause of “cold” is “the reception of Wind Evil or seasonal epidemic toxins”, undoubtedly, here “Wind Evil” is also a general term for external evils.2. “Wind Evil” is a condition for other pathogenic evils rather than an independent causeThe textbook of Basic TCM states[7] that “Cold, Dampness, Dryness, and Heat evils often attach to Wind to invade the human body”, suggesting that other evils can only invade the body by relying on Wind Evil, which has the characteristics of “opening and leaking” and “entering through any opening”. This indicates that the so-called “attachment” is merely a condition for the other five evils to cause disease. This theory lacks practical significance; for example, the Ma Huang Tang syndrome is caused by exogenous Cold Evil, and the treatment is to release the exterior and disperse Cold, yet it is referred to as “Wind Cold Exterior Syndrome”, and the treatment is termed “dispersing Wind Cold”. Clearly, the Ma Huang Tang syndrome has no relation to “Wind”, and Ma Huang Tang is not a “Wind-dispelling” formula. These are all theoretical issues caused by the generalization of the concept of “Wind” that need to be corrected.3. “Wind-dispelling” herbs are actually “Cold-dispersing” herbsCurrently, so-called “Wind-dispelling” herbs are actually “Cold-dispersing” herbs. For example, Du Huo, Fang Feng, and Chuan Wu are typical Cold-dispersing herbs.Thus, “Wind” among the Six Excesses cannot exist as an independent pathogenic cause.2. The theory of “Miscellaneous Qi” cannot directly guide the differentiation and treatment of exogenous diseasesIn addition to the “Six Excesses”, there is another category of causes known as “Miscellaneous Qi” (or Pestilential Qi, Epidemic Qi).The concept of “Miscellaneous Qi” first appeared in the writings of Ming Dynasty physician Wu Youke in his “Treatise on Epidemics: Original Preface”[8]: “The disease of epidemics is neither Wind, nor Cold, nor Summer Heat, nor Dampness, but rather a different kind of qi in the world.” This “different kind of qi” is referred to by Wu as Miscellaneous Qi, Pestilential Qi, or Epidemic Qi.Wu’s understanding of Miscellaneous Qi includes:1. Differences in quality, as noted in the “Treatise on Epidemics: Miscellaneous Qi Theory”[9]: “The Miscellaneous Qi of heaven and earth varies, just as… plants have wild kudzu and poisonous beans, stars have various constellations, insects have venomous snakes and fierce beasts, and earth and stone have sulfur and other minerals; all things have varying degrees of good and evil, thus the toxicity of Miscellaneous Qi also varies.” Wu believed that there are many types of Miscellaneous Qi, and they can be good or evil.2. Selectivity of species, as noted in the “Treatise on Epidemics: Different Types of Qi”[10]: “As for the formless qi, it particularly affects animals, such as bovine plague, ovine plague, avian plague, and duck plague; it is not just human epidemics. However, if cattle are sick, sheep may not be; if chickens are sick, ducks may not be; if humans are sick, animals may not be; the injuries differ due to the different qi involved.”3. Specificity of pathogenicity, as noted in the “Treatise on Epidemics: Miscellaneous Qi Theory”[11]: “Those who come into contact with it will develop various diseases according to their qi… Miscellaneous Qi causes diseases of various types, indicating that the qi is not uniform.”4. Infectiousness, as noted in the “Treatise on Epidemics: Original Preface”[8]: “This qi comes without regard to age or strength; those who come into contact with it will become ill.” Additionally, Wu noted that the diseases caused by Miscellaneous Qi have characteristics of “diversity in manifestation” and “latent onset”.These discussions bear a striking resemblance to the understanding of infectious diseases in Western medicine, suggesting that Wu has revealed the clinical patterns of infectious diseases and even predicted the objective existence of pathogenic microorganisms.However, regarding the treatment of epidemics, relying solely on Wu’s summary of the properties and pathogenic characteristics of “Miscellaneous Qi” does not provide a means for treatment within the TCM knowledge system.Although Wu repeatedly emphasized that “Miscellaneous Qi” is a “different kind of qi” beyond the “Six Excesses”, and he even conceived of finding specific medications, as he stated in the “Treatise on Epidemics: Different Types of Qi”[10]: “For each disease, there is only one medicine; when the medicine is applied, the disease is cured. There is no need for the labor of matching monarch, minister, assistant, and envoy, or the effort of adjusting flavors and dosages”, yet when it comes to specific treatment, TCM still requires differentiation.Thus, the “causes” derived from differentiation that can guide clinical medication still cannot escape the framework of the “Six Excesses”.Based on this understanding, I believe that Wu’s theory of “Miscellaneous Qi” aids in our deeper understanding of the patterns of epidemic onset; however, this theory cannot directly guide TCM in establishing treatment methods for epidemics.Therefore, Wu’s theory of “Miscellaneous Qi” has not been further developed by later generations of physicians.3. Standardization Proposal for Exogenous Pathogenic Factors(1) The “Six Excesses” can be simplified to “Four Excesses”Based on the above understanding, using the essential properties of pathogenic evils as a criterion, I believe that the causes of exogenous diseases can be simplified from the original “Wind, Cold, Summer Heat, Dampness, Dryness, Fire” to “Cold, Heat, Dryness, Dampness”. This will make the clinical diagnosis and treatment of exogenous diseases more standardized and refined.(2) Standardization Proposal for Epidemic Qi (or “Miscellaneous Qi”)“Epidemic Qi” is a hypothesis derived from the study of infectious diseases using macro-observation methods in the absence of technical support for microscopic research, which had significant importance before the establishment of Western infectious disease theory. With the development of Western infectious disease theory, the causes of most infectious diseases have been clarified, thus the hypothesis regarding the causes of infectious diseases has lost its significance.I believe that for infectious diseases with clear causes, it is more reasonable to use Western medical theories. For example, measles, as stated in the “Textbook of TCM Pediatrics”: “Measles is an acute eruptive infectious disease caused by the reception of measles evil (measles virus)”[12], and in the subsequent discussion of causes and mechanisms, it mentions “measles as a Yang toxin” and “measles toxin as an evil”, which is clearly not as straightforward as using the Western medical cause “measles virus”.References[1] Li Jinyong. On the Formation of the Six Excesses Theory in Traditional Chinese Medicine [J]. New Medical Communications, 1979, 12:1-2.[2] Wang Yuanshi. Questioning the “Fire” in the Six Excesses [J]. Journal of Shandong University of Traditional Chinese Medicine, 1981, 4:26-27.[3] Chen Yan. Treatise on the Three Causes and One Disease [M]. Beijing: People’s Health Publishing House, 1983:19.[4] Wang Yuming. The Nature of “Wind Evil” Should Be Divided into Cold and Heat [J]. Jilin Traditional Chinese Medicine, 1993, 2:46.[5] Wang Xingtong. Discussion on the Nature of Wind Evil [J]. Journal of Traditional Chinese Medicine, 1997, 4:50.[6] Tian Delu, ed. TCM Internal Medicine [M]. Beijing: People’s Health Publishing House, 2003:53.[7] Yin Huaihe, ed. Basic Theory of Traditional Chinese Medicine [M]. Shanghai: Shanghai Science and Technology Press, 2009:95.[8] Wu Youke. Treatise on Epidemics, Volume One (Chinese Medicine Great Achievements, Volume Thirteen) [M]. Shanghai: Shanghai Science and Technology Press, 1990:1.[9] Wu Youke. Treatise on Epidemics, Volume Two (Chinese Medicine Great Achievements, Volume Thirteen) [M]. Shanghai: Shanghai Science and Technology Press, 1990:1.[10] Wu Youke. Treatise on Epidemics, Volume Two (Chinese Medicine Great Achievements, Volume Thirteen) [M]. Shanghai: Shanghai Science and Technology Press, 1990:5.[11] Wu Youke. Treatise on Epidemics, Volume Two (Chinese Medicine Great Achievements, Volume Thirteen) [M]. Shanghai: Shanghai Science and Technology Press, 1990:1-2.[12] Wang Chuan, Yu Jianer, eds. TCM Pediatrics [M]. Beijing: China Traditional Chinese Medicine Publishing House, 2012:223.Author of this article:Xiao Xiangru, Professor and Doctoral Supervisor at Beijing University of Chinese Medicine; the first doctoral student in nephrology at the Chinese Academy of Traditional Chinese Medicine; a national key academic leader in nephrology. Awarded the title of “Bethune-style Good Doctor”. Author of “Xiao Xiangru on Treating Kidney Diseases”, “Lectures on Treatise on Cold Damage”, “Specific Formula Evidence”, and “Reconstruction of the Differentiation and Treatment System for Early Exogenous Diseases”.
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“Return to Zhang Zhongjing” series live broadcast replay
First live session:“The Leader of Zhang Zhongjing’s Group Formulas” – The Specific Formula Evidence of Gui Zhi TangSecond session:The Current Situation of TCMThird session: The Reason for the Decline of TCM is the Departure from the Correct Direction of Zhang ZhongjingFourth session: The Path to the Revival of TCM Must Return to Zhang ZhongjingFifth session: “Specific Formula Evidence” is the Standardization System of TCMSixth session: The Correlation of Formula Evidence in the “Treatise on Cold Damage” and the Similarities with Western Clinical GuidelinesSeventh session: The Textbook’s Understanding of the “Holistic Concept” is Incorrect
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