Understanding Exterior SyndromesXiao Xiangru
1. Definition of Exterior Syndromes
The definition of exterior syndrome can be stated as follows: Exterior syndrome is a clinical manifestation caused by the invasion of cold pathogens into the muscle layer, which constrains the defensive qi (wei qi).According to this definition, it is impossible for exterior syndromes to arise from other causes, especially the so-called “wind-heat exterior syndrome”. Exterior syndrome is the initial stage of cold damage, and the Taiyang disease in the “Shang Han Lun” (Treatise on Cold Damage) is an example of exterior syndrome. The section on differentiating Taiyang disease in the “Shang Han Lun” serves as the basis for our current study of exterior syndromes.2. Characteristics of Exterior SyndromesThe characteristic of exterior syndrome is “aversion to cold”.The key points of Taiyang disease state that “the pulse is floating, the head and neck are stiff and painful, and there is aversion to cold”. The floating pulse, stiff neck, and aversion to cold mentioned in the original text are common clinical manifestations of exterior syndrome, but only “aversion to cold” is a specific characteristic, meaning that only “aversion to cold” is a distinctive manifestation of exterior syndrome. The floating pulse and stiff neck are also common in exterior syndrome but are not specific to it; in other words, while these manifestations are common in exterior syndrome, they are not exclusive to it. Therefore, the key to determining whether it is an exterior syndrome is the presence of “aversion to cold”. It is said that “where there is one part of aversion to cold, there must be one part of exterior syndrome”. It can also be understood that “only with one part of aversion to cold can there be one part of exterior syndrome”.The characteristic of “aversion to cold” is that the patient feels cold and is not relieved by adding clothing or warming up. If the patient feels cold and is relieved by adding clothing or warming up, it is termed “fear of cold”, which is a manifestation of Yang deficiency.
3. Causes of Exterior SyndromesThe cause of exterior syndrome is cold pathogens.To study exterior syndrome, one must first study “aversion to cold”. The mechanism of aversion to cold is that cold pathogens bind the exterior, restraining the defensive qi, which prevents it from performing its function of warming the flesh. Because cold is constricting and stagnating, it can bind the muscle layer and obstruct the defensive qi. In other words, only when cold pathogens invade the muscle layer can they bind the defensive qi, leading to aversion to cold and thus exterior syndrome. “Aversion to cold” cannot be caused by other reasons, as other reasons cannot bind the defensive qi, especially heat pathogens cannot bind the defensive qi and cannot lead to “aversion to cold”.
4. Nature of Exterior SyndromesBased on the analysis of the definition of exterior syndrome, the cause is the invasion of cold pathogens into the muscle layer, which restrains the defensive qi, thus its nature is cold.5. Classification of Exterior SyndromesBased on the presence of sweating, exterior syndromes can be classified into exterior excess syndrome and exterior deficiency syndrome, corresponding to Taiyang wind and Taiyang cold damage, namely the Ma Huang Tang (Ephedra Decoction) syndrome and Gui Zhi Tang (Cinnamon Twig Decoction) syndrome.The second section of the “Shang Han Lun” states, “In Taiyang disease, if there is fever and sweating, aversion to wind, and a slow pulse, it is called wind stroke”; the third section states, “In Taiyang disease, whether there is fever or not, there must be aversion to cold, body pain, vomiting, and a tight pulse, it is called cold damage”.The main basis for distinguishing between wind stroke and cold damage is the presence or absence of sweating, not aversion to wind or aversion to cold. Aversion to wind and aversion to cold only differ in degree, not in essence.The manifestation of aversion to wind is that one feels cold when exposed to wind but is comfortable when not; the manifestation of aversion to cold is that even in a warm room, one still feels cold. Although aversion to wind is generally less severe than aversion to cold, their characteristics are the same, as neither is relieved by adding clothing or warming up. A person with aversion to wind will still feel cold even when adding clothing or warming up while exposed to wind.In the “Shang Han Lun”, there is no essential difference between aversion to wind and aversion to cold, as stated in the twelfth section: “In Taiyang wind stroke, Yang is floating and Yin is weak; Yang floating means heat is self-generated, and Yin weak means sweating occurs, with aversion to cold and aversion to wind, fever, nasal congestion, and dry vomiting, Gui Zhi Tang is the main treatment”. This indicates that Taiyang wind stroke can have both aversion to wind and aversion to cold. The causes of wind stroke and cold damage may relate to the patient’s constitution and the severity of cold pathogen invasion; a strong constitution with tight pores may lead to Taiyang cold damage, while a weak constitution with loose pores may lead to Taiyang wind stroke.Thus, I believe that the external pathogenic causes can be simplified from the six excesses to four types: cold, heat, dryness, and dampness. Cold and heat differentiate temperature, while dryness and dampness differentiate humidity. Wind and cold differentiate the degree of cold, as they share the same nature and treatment methods. The essence of summer heat is heat, a special manifestation of heat that is time-limited, occurring in summer when the degree of heat is more severe and often accompanied by dampness. The “Su Wen” (Plain Questions) states, “The period before the summer solstice is the time for heat-related illnesses, while after the summer solstice is the time for summer heat-related illnesses”.Among the four external pathogenic causes, cold pathogens invading the body can cause “aversion to cold”, leading to exterior syndrome; damp pathogens can also cause “aversion to cold”, but with prominent damp characteristics, as dampness is water-like and inherently cold, thus the treatment principles for dampness and resolving exterior syndromes are the same, both using warm acrid herbs; heat and dryness will not cause “aversion to cold”, thus cannot lead to exterior syndrome.6. Concurrent Syndromes with Exterior SyndromesExterior syndrome can exist alone or can occur concurrently with other syndromes, such as concurrent interior heat, water retention, or Yang deficiency, based on clinical manifestations.Among the concurrent syndromes primarily involving exterior syndrome, the concurrent syndromes of wind stroke include Gui Zhi Jia Ge Gen Tang (Cinnamon Twig Decoction with Kudzu) syndrome, Gui Zhi Jia Fu Zi Tang (Cinnamon Twig Decoction with Aconite) syndrome, Gui Zhi Qu Shao Yao Tang (Cinnamon Twig Decoction without Peony) syndrome, Gui Zhi Jia Hou Po Xing Zi Tang (Cinnamon Twig Decoction with Magnolia and Apricot) syndrome, Gui Zhi Qu Shao Yao Jia Fu Zi Tang (Cinnamon Twig Decoction without Peony with Aconite) syndrome, Gui Zhi Jia Fu Zi Tang (Cinnamon Twig Decoction with Aconite) syndrome, and Gui Zhi Xin Jia Tang (Cinnamon Twig Decoction with New Additions) syndrome; the concurrent syndromes of cold damage include Ge Gen Tang (Kudzu Decoction) syndrome and Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) syndrome.Exterior syndrome can also occur concurrently with other channel diseases, such as Chai Hu Gui Zhi Tang (Bupleurum and Cinnamon Twig Decoction) syndrome, which is a concurrent syndrome of wind stroke and Shaoyang disease, and Gui Zhi Ren Shen Tang (Cinnamon Twig and Ginseng Decoction) syndrome, which is a concurrent syndrome of wind stroke and Taiyin disease, and Ma Huang Xi Xin Fu Zi Tang (Ephedra, Asarum, and Aconite Decoction) syndrome, which is a concurrent syndrome of cold damage and Shaoyin disease.
7. Treatment Methods for Exterior SyndromesAccording to the principle in the “Nei Jing” (Inner Canon) that states, “For conditions affecting the skin, induce sweating to resolve it”, the treatment method for exterior syndrome is to induce sweating and resolve the exterior. For exterior excess syndrome, Ma Huang Tang (Ephedra Decoction) is used, while for exterior deficiency syndrome, Gui Zhi Tang (Cinnamon Twig Decoction) is used. The thirty-fifth section of the “Shang Han Lun” states, “In Taiyang disease, if there is headache, fever, body pain, waist pain, joint pain, aversion to wind, and no sweating with wheezing, Ma Huang Tang is the main treatment”; the twelfth section states, “In Taiyang wind stroke, Yang is floating and Yin is weak; Yang floating means heat is self-generated, and Yin weak means sweating occurs, with aversion to cold and aversion to wind, fever, nasal congestion, and dry vomiting, Gui Zhi Tang is the main treatment”.The concurrent treatment of exterior syndrome and other syndromes should follow the principle of prioritizing the exterior and interior based on urgency, which is well reflected in the “Shang Han Lun”.Generally speaking, in cases of concurrent exterior and interior diseases, if the exterior syndrome is predominant and the interior syndrome is not urgent or severe, the exterior should be resolved first, or the treatment should focus on resolving the exterior; if the interior syndrome is urgent or severe, it should be treated first, or the treatment should focus on the interior. For example, in section 106, the treatment of blood stasis syndrome with Tao He Cheng Qi Tang (Peach Pit Decoction) requires resolving the exterior first when there is concurrent exterior syndrome, as blood stasis is not urgent or severe; in section 124, the treatment of blood stasis syndrome with Di Dang Tang (Di Dang Decoction) requires treating blood stasis first even if there is concurrent exterior syndrome, as blood stasis is urgent and severe.Author of this article:Xiao Xiangru, Professor and PhD supervisor at Beijing University of Chinese Medicine; the first PhD in nephrology at the China Academy of Chinese Medical Sciences; a national key academic leader in nephrology. Awarded the title of “Bethune-style Good Doctor”. Author of works such as “Xiao Xiangru on Treating Kidney Diseases”, “Xiao Xiangru’s Lectures on Shang Han Lun”, “Specific Formulas and Syndromes”, and “Reconstructing the Differentiation and Treatment System for Early External Pathogenic Diseases”.
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First live session:“The Leader of Zhang Zhongjing’s Group Formulas” – The Specific Formulas of Gui Zhi TangSecond session:The Current Situation of Traditional Chinese MedicineThird session: The Decline of Traditional Chinese Medicine is Due to Straying from Zhang Zhongjing’s Correct DirectionFourth session: The Path to Reviving Traditional Chinese Medicine Must Return to Zhang ZhongjingFifth session: “Specific Formulas and Syndromes” is the Standardized System of Traditional Chinese MedicineSixth session: The Similarities Between the Correlation of Formulas in the Shang Han Lun and the Graded Recommendations in Western Medical Clinical GuidelinesSeventh session: The Misunderstanding of the “Holistic Concept” in Textbooks
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