Damp-heat disease, caused by the invasion of external damp-heat pathogens, is characterized by: persistent fever without significant elevation, stagnation of Qi, dysfunction of the spleen and stomach, abnormal water metabolism, and a lingering illness that is difficult to resolve. Due to the differences in nature and characteristics between damp-heat diseases and warm diseases, timely and effective differentiation and treatment based on their properties and characteristics is essential. This article discusses the principles of differentiation and treatment of damp-heat diseases.
The differentiation framework for damp-heat diseases—San Jiao differentiation
The San Jiao differentiation was advocated by the famous warm disease scholar Wu Jutong during the Qing Dynasty. In his book “Wenbing Tiaobian,” he categorized warm diseases based on their invasion of the body’s organs into three major categories: upper, middle, and lower Jiao, indicating the vertical transmission pattern of warm diseases from the upper to the middle and lower Jiao, and providing a diagnostic localization of the affected areas. Since damp-heat diseases are caused by the invasion of both damp and heat pathogens, which often manifest initially as a simultaneous attack on the Wei Qi, the development process of damp-heat diseases does not clearly delineate the stages of Wei Qi and Ying Blood, but rather presents a pattern of transmission through the three Jiao. Therefore, it can be said that San Jiao differentiation is most suitable for guiding the differentiation and treatment of damp-heat diseases, which is the basis for this article’s focus on San Jiao differentiation as the framework for damp-heat disease differentiation.
Physiological concept of San Jiao
The term “San Jiao” and its physiological concept first appeared in the “Neijing,” with further elaboration in the “Nanjing.” In summary, there are four main aspects:
1. The channel for the movement of Yang Qi in the body—Qi Dao The “Nanjing, Difficulty 66” states: “San Jiao is the origin of the original Qi, governing the passage of the three Qi, circulating through the five organs and six bowels.” This indicates that San Jiao is governed by the original Qi (referring to the true Qi, or the Qi of the entire body), and its physiological function is to facilitate the movement of the three Qi (Zong Qi, Zhong Qi, Yuan Qi), allowing them to circulate within the body, connecting the five organs, six bowels, and their associated meridians, tissues, and organs. Thus, San Jiao serves as the channel for the movement of Yang Qi in the body, referred to as Qi Dao.
2. The channel for the movement of water and fluids in the body—Shui Dao The “Suwen, Linglan Mijian Lun” states: “San Jiao is the official of drainage, from which the water path emerges.” The term “decide” means to open, and “drain” refers to a water channel. This indicates that San Jiao is the open water channel within the body, which is the pathway for the movement of water and fluids, referred to as Shui Dao.
Since Qi drives the movement of water, Qi Dao and Shui Dao are consistent. San Jiao is both Qi Dao and Shui Dao, meaning that Yang Qi propels the fluids to circulate through the San Jiao channel, distributing them throughout the body. As stated in the “Lingshu, Wulou Jin Ye Bie”: “San Jiao releases Qi to warm the muscles and skin, nourishing the body fluids; if the flow is obstructed, it becomes liquid. In hot weather, the pores open, leading to sweating… In cold weather, the pores close, causing Qi and dampness to stagnate, resulting in retention of fluids in the bladder, leading to urination issues and Qi stagnation.” Thus, San Jiao is the site and channel for the metabolism of fluids in the body, serving as the location and pathway for Qi transformation.
3. Division of the body into upper, middle, and lower regions The “Lingshu, Ying Wei Sheng Hui” states: “The upper Jiao is above the stomach, including the throat and chest… The middle Jiao is located in the stomach… The lower Jiao is the intestines and bladder.” This indicates that the upper Jiao refers to the area above the stomach, including the chest; the middle Jiao refers to the area between the diaphragm and the navel; and the lower Jiao refers to the area below the navel, including the large intestine and bladder. Collectively, these three regions are referred to as San Jiao.
Generally, the organs are categorized anatomically into the three Jiao: the upper Jiao includes the heart, pericardium, and lungs; the middle Jiao includes the spleen, stomach, liver, and gallbladder; the lower Jiao includes the small intestine, large intestine, kidneys, and bladder. It should be noted that due to the close relationship between the stomach and large intestine during warm disease processes, Wu Jutong categorized the pathologies of the large intestine and stomach together in the middle Jiao; similarly, the pathologies of the liver and kidneys are categorized together in the lower Jiao.
4. Physiological functions of the upper, middle, and lower Jiao The “Lingshu, Ying Wei Sheng Hui” summarizes: “The upper Jiao is like mist, the middle Jiao is like fermentation, and the lower Jiao is like a drainage channel.” This means that the middle Jiao digests and transforms food and fluids, similar to fermentation, with the refined substances transported by the spleen to the upper Jiao. The upper Jiao, including the heart and lungs, distributes the refined substances throughout the body, nourishing it. The lower Jiao, including various organs, transforms the waste produced from metabolism into urine and feces, continuously expelling them from the body. In summary, San Jiao governs the Qi transformation in the body, serving as the site and channel for the digestion, absorption, transportation of refined substances, and the excretion of waste.
5. One of the organs responsible for transformation in the body The “Suwen, Wuzang Bie Lun” states: “The stomach, large intestine, small intestine, San Jiao, and bladder are the five organs that are born from the weather; their Qi resembles the heavens, thus they excrete rather than store, receiving the turbid Qi from the five organs, known as the organs of transformation.” This discussion of the physiological concept of San Jiao views it as one of the organs responsible for transformation in the body, with the physiological function of excreting the turbid Qi from the body.
6. The “Lingshu, Ben Shu” states: “San Jiao is the official of the middle drainage, from which the water path emerges, belonging to the bladder, and is the unique official.” The term “unique” here means one of a kind, indicating that San Jiao is the largest organ in the body. Ming Dynasty scholar Zhang Jingyue referred to it in “Leijing, Zangxiang Lei” as “the organ outside the viscera, within the body, encompassing all organs, the largest organ.” Thus, San Jiao is both one of the organs responsible for transformation in the body and the largest among them, encompassing all the organs within the body. Therefore, viewing San Jiao as a specific organ of transformation and as a division of the body into upper, middle, and lower regions is consistent. In other words, San Jiao, as the largest “unique official” in the body, encompasses all the organs belonging to the upper, middle, and lower Jiao.
In summary, from a physiological perspective, San Jiao includes all the organs of the upper, middle, and lower Jiao, making it the largest organ of transformation. It is the site and channel for the movement of Yang Qi and fluids in the body, the digestion and absorption of food, the transportation of refined substances, and the excretion of waste, all occurring within the “unique official” of San Jiao. Therefore, the physiological functions of San Jiao actually summarize the physiological functions of the organs belonging to the upper, middle, and lower Jiao.
Pathogenesis and clinical characteristics of damp-heat syndrome in San Jiao
Damp-heat diseases are most prevalent during the rainy season, typically resulting from the simultaneous invasion of both damp and heat pathogens; or from external dampness leading to internal heat; or from a constitution predisposed to damp-heat being affected by seasonal pathogens, causing an internal-external interaction that leads to illness. The pathogenesis can be briefly summarized as: damp-heat pervades, Qi stagnation occurs, leading to dysfunction of the organs associated with the three Jiao. Since the disease is caused by the combination of damp and heat pathogens, the pathological changes exhibit characteristics of both damp and heat. Dampness is a Yin pathogen, heavy and turbid, obstructing Qi; heat is a Yang pathogen, characterized by its ability to steam and disperse. The combination of these two pathogens with different properties determines the various clinical manifestations of damp-heat diseases, which can be summarized into four main characteristics. First, there is a strong seasonal aspect, with a peak incidence during the transition from summer to autumn. During this time, the climate is hot, with abundant rainfall, causing heat to steam and dampness to move, easily invading the body and causing illness.
Second, the spleen and stomach are the centers of pathology, leading to Qi stagnation and abnormal water metabolism. The spleen governs dampness and dislikes dampness; when damp-heat pathogens invade, they often obstruct the spleen and stomach, causing dysfunction in their ascending and descending functions, leading to the accumulation of dampness. The more dampness accumulates, the more the spleen and stomach are obstructed; the more the spleen and stomach are obstructed, the more dampness stagnates, hence damp-heat diseases often center around the spleen and stomach. Since dampness is a pervasive pathogen, especially when combined with heat, the steaming of heat causes dampness to move, making it easier to spread throughout the body, resulting in simultaneous symptoms both inside and outside. The pervasiveness of damp-heat leads to Qi stagnation, causing poor Qi transformation and obstruction of the water pathway in the San Jiao, hence clinical manifestations of abnormal water metabolism are common in damp-heat diseases.
Third, contradictory symptoms are often observed clinically. The simultaneous presence of damp and heat pathogens means that each exhibits its own characteristics while also influencing each other, resulting in a state of damp-heat entanglement, where dampness obstructs heat and heat steams dampness, leading to the emergence of contradictory symptoms. For example, there may be fever without significant elevation, or the skin may feel cool upon initial touch but warm upon prolonged contact; the pulse may be not rapid but rather soft and slow; the complexion may not be red but pale yellow; the spirit may not be agitated but rather dull; there may be dryness of the mouth without a desire to drink; and there may be constipation for several days without dryness but rather loose stools.
Fourth, the disease course is long and difficult to resolve. Dampness and heat are intertwined, like oil in water, making them difficult to separate. Dampness is sticky and difficult to eliminate quickly; if the tangible dampness is not expelled, the intangible heat will remain trapped within the dampness, unable to resolve. The more dampness stagnates, the more heat accumulates; the more heat steams, the more dampness becomes sticky, leading to a situation that is hard to resolve, often prolonging the illness.
Initially, damp-heat diseases often first affect the upper Jiao, then gradually progress to the middle and lower Jiao, as Wu Jutong stated: “starting from the upper Jiao, ending in the lower Jiao.” According to San Jiao differentiation, the development of damp-heat diseases can be divided into three major categories: upper Jiao damp-heat syndrome, middle Jiao damp-heat syndrome, and lower Jiao damp-heat syndrome. These three categories of syndromes mark the central areas of pathology and the stages of the disease course in the development of damp-heat diseases.
Upper Jiao damp-heat syndrome occurs when damp-heat pathogens invade the lungs through the mouth, nose, and skin, leading to dysfunction of the Wei Qi, impaired lung function, and abnormal water metabolism. This is the initial stage of damp-heat diseases. Although the pathogens enter from the exterior, damp-heat often pervades internally, affecting both the lungs and spleen, hence early damp-heat diseases often present with simultaneous exterior and interior symptoms. The characteristics of this syndrome include: aversion to cold, fever, persistent fever without significant elevation, heaviness and pain in the head and body, a white and greasy tongue coating, and a soft pulse. Additionally, symptoms from the middle and lower Jiao may also be present, such as abdominal fullness and poor appetite, and difficulty urinating.
Upper Jiao damp-heat syndrome, in addition to lung involvement, may also present with damp-heat stagnation, leading to phlegm turbidity that obscures the heart. The characteristics of this syndrome include: persistent fever without significant elevation, a dull expression, mental dullness, intermittent consciousness, a white and greasy tongue coating, and a soft and slippery pulse.
Middle Jiao damp-heat syndrome occurs when damp-heat pathogens obstruct the spleen and stomach, leading to dysfunction in their ability to transform and transport, causing Qi stagnation and imbalance in ascending and descending functions. Due to individual differences in constitution and the varying severity of damp and heat pathogens, or the influence of medications during treatment, this syndrome can be categorized into three types: dampness heavier than heat, equal severity of damp and heat, and heat heavier than damp. Although they differ, they all share the common characteristic of dysfunction in the ascending and descending functions of the spleen and stomach, leading to symptoms such as: abdominal fullness, poor appetite, loose stools, a greasy tongue coating, and a soft pulse. Due to the pervasiveness of damp-heat, symptoms from the upper and lower Jiao, such as heaviness and pain in the head and body, and difficulty urinating, may also be present simultaneously.
Lower Jiao damp-heat syndrome occurs when damp-heat pathogens invade the lower Jiao. Due to the entanglement of dampness and heat, heat is trapped within the dampness, hence it generally does not damage the liver blood or kidney essence, but rather causes damp-heat stagnation in the bladder or small and large intestines, leading to abnormal water metabolism and dysfunction in the transmission of food. Although there may be distinctions between dampness heavier than heat and heat heavier than damp, the common characteristics include: obstruction in urination or defecation, a greasy tongue coating, and a soft pulse. Due to the pervasiveness of damp-heat, symptoms from the upper and middle Jiao, such as heaviness and pain in the head and body, and abdominal fullness, may also be present simultaneously.
Transmission patterns and interrelationships of damp-heat syndromes in San Jiao
As seen above, the transmission pattern of damp-heat diseases generally follows the sequence of upper Jiao damp-heat syndrome → middle Jiao damp-heat syndrome → lower Jiao damp-heat syndrome. However, due to the pervasiveness of damp-heat, the upper Jiao can affect the middle and lower Jiao; the middle Jiao can affect the upper and lower Jiao; and the lower Jiao can also affect the middle and upper Jiao. This characteristic of damp-heat syndromes, where one area influences others, is determined by the diffuse nature of the pathogenic factors.
Due to individual differences in constitution and the pathways of pathogen invasion, the transmission patterns of damp-heat diseases along the upper, middle, and lower Jiao are not fixed. For instance, if the pathogen enters through the mouth, it may initially manifest in the middle Jiao; if the pathogen invades from below, it may initially affect the lower Jiao. However, regardless of how the occurrence and development vary, as long as the pathogenesis and characteristics of the damp-heat syndromes in the upper, middle, and lower Jiao are understood, the key to differentiation and treatment can be grasped. Thus, San Jiao differentiation holds significant clinical guidance for the differentiation and treatment of damp-heat diseases.
In summary, its clinical significance includes two aspects: first, it summarizes the three different syndromes at various stages of damp-heat disease development; second, it indicates the location of the damp-heat pathogens and their general pattern of vertical progression from the upper to the lower Jiao. These two aspects are interconnected, providing a reliable basis for clinical differentiation and treatment of damp-heat diseases and for assessing their prognosis.
Principles of treatment for damp-heat diseases
Eliminate dampness and clear heat
Damp-heat diseases are caused by the simultaneous invasion of two different pathogenic factors, dampness and heat, hence treatment should focus on both eliminating dampness and clearing heat. However, since dampness and heat are intertwined, with heat trapped within dampness, if dampness is not eliminated, heat cannot be cleared. Therefore, the primary focus of treatment is to eliminate dampness. Given that the centers of pathology in the upper, middle, and lower Jiao differ, treatment should target the specific area of pathology with appropriate medications, guiding the expulsion of pathogens. However, since damp-heat pathogens can easily diffuse throughout the three Jiao, treatment must also consider all three Jiao. The specific treatment methods for damp-heat in the three Jiao are as follows:
1. Spicy-warm dispersing and aromatic dampness transformation, referred to as the spicy-dispersing aromatic transformation method, is suitable for upper Jiao damp-heat syndrome. This involves using spicy-warm and aromatic herbs that lightly disperse and transform dampness and heat to promote lung Qi, unblocking the skin pores, allowing for slight sweating to gradually resolve the dampness. Commonly used herbs include: Huo Xiang (Agastache), Bai Zhi (Angelica dahurica), Su Ye (Perilla leaf), Xiang Ru (Elsholtzia), and Cang Zhu (Atractylodes). Pei Lan (Eupatorium) and Qing Hao (Artemisia annua), although not spicy-warm, have aromatic dispersing properties and can also be included in clinical practice. This aligns with Wu Jutong’s statement in “Wenbing Tiaobian”: “Treat the upper Jiao as if it were a feather; it must be lifted lightly.”
2. Spicy-warm to open stagnation and bitter-warm to dry dampness, referred to as the spicy-opening bitter-descending method, is suitable for middle Jiao dampness heavier than heat syndrome. This involves pairing spicy-warm and bitter-warm herbs to open stagnation and dry dampness, restoring the balance of the spleen and stomach’s ascending and descending functions. Commonly used herbs include: Ban Xia (Pinellia), Cang Zhu (Atractylodes), Sha Ren (Amomum), Bai Dou Kou (White cardamom), Cao Guo (Tsaoko fruit), Hou Po (Magnolia bark), Zhi Shi (Bitter orange), Da Fu Pi (Areca peel), Chen Pi (Tangerine peel), and Bai Zhu (Atractylodes). This aligns with Wu Jutong’s statement: “Treat the middle Jiao as if it were a scale; it must be balanced to be stable.”
3. Bitter-cold to clear heat and dry dampness, suitable for middle Jiao damp-heat equally severe or heat heavier than damp syndrome. This involves selecting bitter-cold herbs to achieve the goal of clearing heat and drying dampness. Commonly used herbs include: Huang Qin (Scutellaria), Huang Lian (Coptis), and Zhi Zi (Gardenia). It should be noted that the use of bitter-cold herbs for treating damp-heat diseases should be approached with caution; they should only be used when heat is heavier than dampness. If damp-heat is equally severe, spicy-warm and bitter-warm herbs can be used together with bitter-cold herbs to achieve both heat clearing and dampness drying. If dampness is severe, bitter-cold herbs should be avoided to prevent them from freezing and trapping dampness, making the condition difficult to resolve.
4. Lightly draining to promote urination, suitable for lower Jiao damp-heat syndrome. This involves using lightly draining herbs to promote urination and expel dampness through urination. Commonly used herbs include: Hua Shi (Talc), Tong Cao (Tetrapanax), Fu Ling (Poria), Sheng Yi Yi Ren (Job’s tears), Ze Xie (Alisma), Zhu Ling (Polyporus), and Che Qian Zi (Plantago). If heat is heavier than dampness in the lower Jiao, bitter-cold herbs that clear heat and promote urination, such as Zhi Zi (Gardenia), Mu Tong (Akebia), and Zhu Ye (Bamboo leaf), can be added to the lightly draining herbs.
5. Consideration of all three Jiao. Since damp-heat easily diffuses throughout the three Jiao, in clinical practice, treatment should not only target the center of pathology but also consider all three Jiao. This means treating the upper Jiao without neglecting the middle and lower Jiao; treating the middle Jiao without neglecting the upper and lower Jiao; and treating the lower Jiao without neglecting the middle and upper Jiao. This is why spicy-dispersing aromatic transformation, spicy-opening bitter-descending, and lightly draining herbs are often used together in clinical prescriptions.
6. Strengthening the spleen and benefiting Qi, awakening the stomach and promoting digestion. The spleen governs transformation and transportation, while the stomach governs receiving and descending. In damp-heat diseases, damp-heat easily obstructs the spleen and stomach, leading to dysfunction in their ascending and descending functions. Therefore, during treatment, it is essential to include herbs that strengthen the spleen and benefit Qi, such as Fu Ling (Poria), Sheng Yi Yi Ren (Job’s tears), and Bai Zhu (Atractylodes); and herbs that awaken the stomach and promote digestion, such as Sha Ren (Amomum), Bai Dou Kou (White cardamom), Shan Zha (Hawthorn), Shen Qu (Fermented grain), Mai Ya (Barley sprout), and Chao Sheng Yi Yi Ren (Fried Job’s tears).
7. Regulating Qi and unblocking stagnation, opening the lung Qi. Dampness is heavy and turbid, easily obstructing Qi. If Qi is not smooth, the water pathway will be obstructed, and dampness cannot be expelled. Therefore, it is essential to include herbs that regulate Qi and unblock stagnation in the treatment to promote smooth Qi flow, allowing dampness to follow. Commonly used herbs include: Hou Po (Magnolia bark), Zhi Shi (Bitter orange), Da Fu Pi (Areca peel), Chen Pi (Tangerine peel), Huo Xiang (Agastache), and Su Ye (Perilla leaf). The lungs govern the regulation of the water pathway; if lung Qi is unblocked, the water pathway will be smooth, allowing damp-heat to be expelled. Therefore, herbs that open lung Qi, such as Xing Ren (Apricot kernel) and Jie Geng (Platycodon), are often included in the treatment of damp-heat diseases. Additionally, spicy-dispersing aromatic herbs also have the function of opening lung Qi.
Contraindications for the treatment of damp-heat diseases
Avoid excessive sweating
When damp-heat pathogens invade the upper Jiao, obstructing the skin pores, it is advisable to use spicy-dispersing aromatic herbs to promote sweating and allow the pathogens to be expelled through slight sweating. However, strong spicy and warm herbs like Ma Huang (Ephedra) and Gui Zhi (Cinnamon twig) should be avoided. Due to the sticky nature of dampness, it is difficult to eliminate quickly; only slight sweating can gradually resolve it. Using Ma Huang or Gui Zhi to induce excessive sweating may not only fail to expel dampness but also exacerbate heat and dampness, leading to obstruction of the heart and clouding of the mind, resulting in symptoms such as confusion, deafness, and loss of consciousness. As Wu Jutong stated: “If sweating occurs, it may lead to confusion and deafness, and in severe cases, loss of consciousness and unwillingness to speak.”
Avoid excessive purging
When damp-heat pathogens obstruct the gastrointestinal tract, leading to stagnation of Qi, it is advisable to avoid using strong purgatives like Da Huang (Rhubarb) and Mang Xiao (Sodium sulfate). Due to the sticky nature of dampness, it cannot be expelled with a single purge; using such purgatives may not only fail to expel dampness but also damage the spleen Yang, leading to continuous diarrhea and loss of control. As Wu Jutong stated: “If purged, it may lead to continuous diarrhea.”
Avoid tonics
In damp-heat diseases, symptoms such as afternoon fever and thirst may appear, which are caused by dampness rather than Yin deficiency. If misdiagnosed as Yin deficiency and tonics like Sheng Di Huang (Rehmannia) or Mai Dong (Ophiopogon) are used, it may lead to further dampness accumulation, making the condition difficult to resolve. As Wu Jutong stated: “If moistened, the disease will deepen and not resolve.”
Avoid warming tonics
Dampness is a Yin pathogen that easily injures Yang Qi. During the course of damp-heat diseases, due to dampness obstructing Qi, Yang Qi may not circulate, leading to symptoms such as a pale yellow complexion, cold extremities, and fatigue. This is due to dampness obstructing Qi rather than a deficiency of cold; if misdiagnosed as Yang deficiency and warming tonics like Dang Shen (Codonopsis) or Huang Qi (Astragalus) are used, it may further obstruct the spleen and stomach, exacerbating damp-heat and worsening the condition. As Ye Tianshi stated: “One should not hastily use tonics for Yang deficiency, for fear that although the smoke may cease, there is still fire in the ashes.”
Dietary considerations
During the course of damp-heat diseases and their recovery period, the spleen and stomach may be sluggish, so a light and soft diet is advisable. Sweet, sticky, oily, greasy, cold, and hard-to-digest foods should be avoided to prevent further damage to the spleen and stomach and exacerbation of the condition.
Exciting content continues
Recommended high-quality online courses from Shizhen Education
-
Chinese Acupuncture
-
Fundamentals of Acupuncture
-
Basic Theory of TCM, a stepping stone to learning Chinese medicine
-
24 Solar Terms, Meridians, Acupoints, and Health Preservation
-
Pediatric Tuina Special: Comprehensive Guide to Common Pediatric Diseases
-
One Moxa Stick to Make You a “Family TCM Practitioner”
-
Taoist Wuji Health Preservation Course
-
Thread-Embedding Needle Knife Therapy
Shizhen Education
Key sections· Click the title to enter
Instructor Introduction Training Highlights Course Registration
Health Mall Online Classroom
For online learning courses, please click Read the original text