1. Standards for Differentiating Xu and Shi The primary criterion for distinguishing between Xu (deficiency) and Shi (excess) is the pulse. A strong pulse indicates Shi, and one that is weak indicates Xu. The differentiation between Shi and Xu based on the strength of the pulse is very clear and accurate. In the context of the six meridians, a strong pulse belongs to the three Yang diseases, while a weak pulse belongs to the three Yin diseases. In the differentiation of the organs, a strong pulse indicates a disease of the six fu organs, while a weak pulse indicates a disease of the five zang organs. In the eight principles differentiation, a strong pulse represents Yang, indicating Shi; a weak pulse represents Yin, indicating Xu. 2. Standards for Differentiating Cold and Heat Currently, the simplest way to differentiate between Cold and Heat is by examining the tongue coating, focusing on whether it is moist or dry, rather than its color (yellow or white). A moist tongue coating indicates Cold, while a dry coating indicates Heat. Therefore, the tongue coating in Taiyang disease must be moist, while in Yangming disease, it must be dry. The same applies to patients with Xu Heat; a weak pulse and a dry tongue coating indicate Xu Heat, such as in the case of Huanglian Ejiao Tang (Coptis and Donkey-hide Gelatin Decoction), where the tongue surface must be dry, never moist. In patients with Xu Cold, the tongue coating must be moist, such as in the case of Zhenwu Tang (True Warrior Decoction). By observing the moisture and dryness of the tongue coating, we can differentiate between Cold and Heat. The reasoning is simple: Cold means less water vapor, resulting in a moist tongue surface; Heat means water has turned into vapor, resulting in a dry tongue surface. The only difficult differentiation is between Damp Heat and Cold Damp, as both present with a greasy coating. It is commonly believed that a yellow greasy coating indicates Damp Heat, while a white greasy coating indicates Cold Damp, which is incorrect; yellow coating indicates Heat, while white indicates Cold is not precise. Any greasy coating that is slippery indicates Cold Damp, while a non-slippery greasy coating indicates Damp Heat. Therefore, when encountering a greasy coating, there is no need to consider the color of the tongue coating; just observe the degree of moisture on the tongue surface. △ Once this issue is resolved, the general direction of treatment in clinical practice will not go wrong. A strong or weak pulse differentiates Xu and Shi, while the moisture and dryness of the tongue coating differentiate Cold and Heat. As the saying goes, Yin and Yang, Exterior and Interior, Cold and Heat, Xu and Shi. By clearly distinguishing these principles, we can have confidence in treating diseases. When combined, the nature of the disease can be fully understood. In clinical practice, diseases often present with mixed Cold and Heat, such as in the case of Wumei Wan (Mume Pill), where the patient’s tongue coating may be moist in some areas and dry in others. Differentiating Cold and Heat is crucial in treatment. For example, in water diseases, there are hot water diseases and cold water diseases; in blood stasis, there are hot blood stasis and cold blood stasis; in cough, there are hot cough and cold cough, etc. The pathogenesis can be summarized in nineteen points: “All turbid water and liquid belong to Heat; all clear and cool water and liquid belong to Cold.” This method uses water and liquid to differentiate between Cold and Heat, which is simple and easy to learn. For patients with colds, if they have clear nasal discharge, the discharge is as clear as water, indicating clear and cool liquid, which belongs to Cold, thus it is cold water. Cold water needs to be warmed, using herbs like Ma Huang (Ephedra) and Gui Zhi (Cinnamon Twig), or ginger and brown sugar water; one must never use cooling herbs that clear Heat and detoxify. For wounds that are festering or patients with otitis media who do not heal for a long time, using antibiotics is ineffective, and if the pus is clear and thin like water, it is also called clear and cool liquid, which belongs to Cold, thus it is cold water. Additionally, a weak pulse indicates Xu. In summary, this is Xu Cold, which requires warming and tonifying; one must never use cooling herbs that clear Heat and detoxify, but should use formulas like Shi Quan Da Bu Tang (All-Inclusive Great Tonifying Decoction) or Wu Ji Bai Feng Wan (Black-Bone Chicken and White Phoenix Pill). If a child is drooling, one must determine the nature of the saliva. Clear and thin saliva indicates cold water, which needs to be warmed and tonified, such as with Si Jun Zi Tang (Four Gentlemen Decoction); if the saliva is foul-smelling and turbid, it indicates hot water, and all turbid water and liquid belong to Heat. At this time, if the pulse is strong, use Xie Huang San (Drain the Yellow Powder). In the differentiation of liquids, clear and thin liquids, cool to the touch, and tasteless are cold water; turbid, hot liquids with a foul taste are hot water. For example, clear tears are cold water, while turbid tears are hot water. For nasal discharge, clear and thin indicates Cold, while thick and turbid indicates Heat. Clear, thin phlegm that is easy to expectorate is Cold, such as in the case of Xiao Qing Long Tang (Minor Blue Dragon Decoction); thick and yellow phlegm indicates Heat. Some patients have complex conditions, with clear nasal discharge and yellow, thick phlegm, indicating external Cold and internal Heat, treated with Ma Xing Shi Gan Tang (Ephedra, Apricot Kernel, Gypsum, and Licorice Decoction). Similarly, vomit that is odorless is cold water, while sour and foul-smelling vomit is hot water. Clear and thin saliva indicates Cold, while thick and turbid saliva indicates Heat. For women, a white, clear, and odorless discharge indicates Cold, while thick, yellow, and foul-smelling discharge indicates Heat. Urination can also serve as a differentiation indicator; clear and thin urine that is white indicates Cold, which is cold water; yellow, red, and scanty urine indicates Heat, which is hot water. Loose stools that are clear and thin like water and odorless indicate cold water, which can be treated with Wu Ling San (Five-Ingredient Powder with Poria); foul-smelling stools with pus and blood indicate hot water, and Wu Ling San should not be used. In clinical diagnosis, one can use a strong or weak pulse to differentiate Xu and Shi, and clear or turbid liquids to differentiate Cold and Heat. Some may ask, if one cannot differentiate Cold and Heat through liquids, what should be done? In this case, another method can be used, which is to differentiate based on aversion to cold or heat; aversion to cold indicates Cold, such as in Taiyang disease; aversion to heat indicates Heat, such as in Yangming disease; aversion to both cold and heat indicates Shaoyang disease. One can also differentiate based on preference for cold or hot drinks; preference for cold drinks indicates Heat, while preference for hot drinks indicates Cold; alternating preferences indicate mixed Cold and Heat. Clinical diseases are complex, but regardless, the basic concepts of differentiation must be clear. If one cannot differentiate the simple cases, how can they handle the complex ones? Fu Ling (Poria) can resolve cold water, while Gan Sui (Euphorbia) resolves hot water. Da Huang Gan Sui Tang (Rhubarb and Euphorbia Decoction) addresses the mixture of blood and water, which must be turbid, thus it is hot water, hence Gan Sui is used; postpartum weakness treated with Ejiao (Donkey-hide Gelatin). Taking sweating as an example, cold sweat indicates Cold, while hot sweat indicates Heat; tasteless sweat indicates Cold, while foul-smelling sweat indicates Heat; non-sticky sweat indicates Cold, while sticky sweat indicates Heat. In the Shang Han Lun (Treatise on Cold Damage), it states: “If a patient has a high fever but desires to wear more clothes, it indicates Heat on the surface and Cold in the marrow; if the body is very cold but the patient does not want to wear clothes, it indicates Cold on the surface and Heat in the marrow.” Analysis: A patient with a hot body who wants to wear more clothes is afraid of Cold, which clearly indicates Cold. A patient with a cold body who does not want to wear clothes is afraid of Heat, indicating a Heat condition. Some patients with shoulder periarthritis may have a cold shoulder but must expose it while sleeping at night to feel comfortable, indicating a Heat condition. Some patients may have cold feet at night but prefer to extend them outside the blanket, which also indicates a Heat condition; if the pulse is strong, use Si Ni San (Frigid Extremities Powder), and if weak, use Xiao Jian Zhong Tang (Minor Construct the Middle Decoction). The Sage of Medicine also introduced special cases: sometimes fearing Cold and sometimes fearing Heat; if the pulse is strong, it indicates Shaoyang disease, and if weak, it indicates Jueyin disease, which is called alternating Cold and Heat. Differentiating between Cold and Heat, Xu and Shi is also an important aspect of clinical diagnosis and treatment. In the Wang Xiu Shan Clinical Notes, it is recorded that a worker contracted a cold in winter, and after two or three days, he used a bath to induce sweating, but by midnight, his condition worsened, with a red face, slight fever, frequent sweating, aversion to cold, and shortness of breath, with a moist tongue and six pulses that were weak and almost absent. This indicates true Cold internally and false Heat externally, belonging to Shaoyin. I prescribed Si Wei Hui Yang Yin (Four-Ingredient Return Yang Decoction) and he recovered. Ingredients: 6g Dang Shen (Codonopsis), 3g each of Fu Zi (Aconite), Zhi Gan Cao (Honey-fried Licorice), and Pao Jiang (Blast-fried Ginger). Decoction for oral administration. Note: In winter, contracting a cold and using a bath to induce sweating does not resolve the illness, which is considered a bad condition, but is actually a case of Shaoyin Yin excess and Yang deficiency. The Shang Han Lun states, “If after two or three days of cold damage, the Yangming and Shaoyang patterns are not seen, it indicates that it is not transmissible.” The pulse and symptoms of cold damage are evident, and treatment should not be reversed. Now, using a bath to induce sweating, as described by Zhongjing, “If one uses cold water to wash, it is like pouring it in,” seems plausible but is not. Bathing to induce sweating should be done with hot water; if the body is strong and the pathogen is weak, one can sweat and resolve the illness. However, if the body is inherently Yang deficient, using hot water to steam will force sweating, which will inevitably damage Yang, leading to frequent sweating and shortness of breath, thus injuring Shaoyin. By midnight, Yang declines and Yin rises, resulting in aversion to cold, a red face, and slight fever. The formula used is Si Wei Hui Yang Yin, which treats the deficiency of the original Yang, which is critical at that moment. The Jing Yue Quan Shu states, “Si Wei Hui Yang Yin treats the collapse of the original Yang, which is in danger at any moment.” “Si Ni, Ba Wei, and Li Yin Decoctions, and Hui Yang Yin are all similar to Si Wei Hui Yang Yin.” The analysis shows that the six pulses are weak and almost absent, indicating a Xu condition. A moist tongue indicates a Cold condition. Finally, it is determined to be a Xu Cold Shaoyin aversion to Cold condition, treated with Si Wei Hui Yang Yin. 3. Standards for Differentiating Exterior and Interior In determining the location of the disease, is it in the exterior or the interior? What method is used for judgment? The Sage of Medicine has strict regulations on this. The Jin Gui Yao Lue (Essential Prescriptions of the Golden Cabinet) states: The first section on the diseases of the organs, meridians, and their pulse patterns states: If the patient’s pulse is floating, the disease is in the exterior; if floating is in the rear, the disease is in the interior. If there is low back pain and stiffness, the patient cannot walk, and there is shortness of breath, it is severe. This text discusses that a floating pulse at the cun position indicates an exterior disease; a floating pulse at the chi position indicates an interior disease. Here, the Sage of Medicine omitted a sentence, which is that a floating pulse at the guan position indicates a disease that is half exterior and half interior. This is inevitable and self-evident. To clarify this issue, one must first understand the concept of the unique pulse. Taking the left hand pulse as an example, the left hand pulse is divided into three parts: cun, guan, and chi. The unique pulse refers to the pulse in the cun, guan, and chi that is different from the other two. For example, if the left cun pulse is floating, the left guan pulse is deep, and the left chi pulse is deep, then here, the guan and chi pulses are both deep, and only the cun pulse is floating, making the cun pulse the unique pulse, which is called floating pulse, also known as cun pulse floating. If the cun pulse is deep, the guan pulse is deep, and the chi pulse is floating, it is also called floating pulse. If the cun pulse is deep, the guan pulse is floating, and the chi pulse is deep, it is still called floating pulse. Thus, the floating pulse is determined based on the position of the pulse. Cun pulse floating indicates exterior disease; chi pulse floating indicates interior disease; guan pulse floating indicates half exterior and half interior disease. Once the concept of floating pulse is understood, and the significance of the position of the floating pulse is clear, one can study the Shang Han Lun with clarity. Article 12 states: In Taiyang wind, Yang is floating and Yin is weak… Gui Zhi Tang (Cinnamon Twig Decoction) is the main treatment. Analysis: Yang floating refers to the cun pulse floating, and Yin weak refers to the chi pulse being deep; in fact, the guan pulse is also deep, which indicates an exterior disease. Article 21 states: In Taiyang disease, after purging, if the pulse is rapid and there is fullness in the chest, Gui Zhi Qu Shao Yao Tang (Cinnamon Twig Decoction with Peony) is the main treatment. Analysis: In a case of great Yang disease, if purging is mistakenly done, the pulse remains floating at the cun position, while the guan and chi pulses are deep, and one should still use the method to release the exterior, but with fullness in the chest, Gui Zhi Qu Shao Yao Tang is used. Article 25 states: After taking Gui Zhi Tang, if there is profuse sweating and the pulse is large, continue with Gui Zhi Tang. Analysis: In Taiyang disease, after taking Gui Zhi Tang, if there is profuse sweating and the cun pulse is large while the guan and chi pulses are not large, since the pulse is at the cun position, the disease is in the exterior, and one should release the exterior, thus Gui Zhi Tang is used. Article 26 states: After taking Gui Zhi Tang, if there is profuse sweating followed by great thirst that does not resolve, and the pulse is large, Bai Hu Jia Ren Shen Tang (White Tiger Decoction with Ginseng) is the main treatment. Analysis: In Taiyang disease, after taking Gui Zhi Tang, if profuse sweating occurs, leading to thirst and restlessness, with the chi pulse being large, it is determined to be an interior disease, belonging to Yangming disease, and since the pulse is large and there is profuse sweating, it indicates an exterior symptom of Yangming disease, thus Bai Hu Jia Ren Shen Tang is used. In Articles 25 and 26, both have a large pulse, which is a unique pulse, but the positions are different, thus different prescriptions are used. Article 29 states: In cold damage, if the pulse is floating, with spontaneous sweating, frequent urination, restlessness, and slight aversion to cold, with leg cramps, this is a mistake to attack the exterior with Gui Zhi Tang. Article 30 states: If the cun pulse is floating and large, it indicates wind; large indicates deficiency, wind causes slight fever, and deficiency leads to cramping of the legs, resembling Gui Zhi Tang, thus Fu Zi (Aconite) is added to promote sweating, as Fu Zi warms the meridians and rescues Yang. Analysis: The patient has a floating cun pulse, but it is floating and weak. Floating at the cun indicates an exterior disease, while weakness indicates a Shaoyin disease; thus, it is a Shaoyin exterior disease, and Gui Zhi Tang with Fu Zi is prescribed. Article 37 states: In Taiyang disease, after ten days, if the pulse is floating and thin, with a desire to sleep, the exterior has been resolved. If there is fullness in the chest and pain in the hypochondrium, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is used; if the pulse is only floating, Ma Huang Tang (Ephedra Decoction) is used. Analysis: A floating and thin guan pulse, with a desire to sleep, indicates a half exterior and half interior disease, treated with Xiao Chai Hu Tang. If the cun pulse is floating, Ma Huang Tang is used. Due to the different positions of the floating pulse, different prescriptions are used, just like in Articles 25 and 26. Of course, due to the different positions of the floating pulse, patients will also exhibit different symptoms; for example, if the guan pulse is floating, the patient may experience fullness in the chest and pain in the hypochondrium. Article 38 states: In Taiyang wind, if the pulse is floating and tight, with fever, aversion to cold, body aches, and no sweating but restlessness, Da Qing Long Tang (Major Blue Dragon Decoction) is the main treatment. Analysis: The tight floating pulse refers to the cun pulse being floating and tight, while the guan and chi pulses are not floating and tight. Article 39 states: In cold damage, if the pulse is floating and slow, the body does not ache but feels heavy, sometimes light, without Shaoyin symptoms, Da Qing Long Tang is the main treatment. Analysis: A floating and slow cun pulse indicates the need to release the exterior. Why emphasize the absence of Shaoyin symptoms? Because a floating and slow pulse with strength indicates Taiyang disease, which requires releasing the exterior; if the floating and slow pulse is weak, it indicates a Shaoyin disease, which requires warming and releasing the exterior. Article 42 states: In Taiyang disease, if the exterior symptoms have not resolved and the pulse is floating and weak, one should induce sweating; Gui Zhi Tang is appropriate. Analysis: A weak floating pulse indicates the cun pulse is floating, while the guan and chi pulses are deep. A floating and weak cun pulse indicates the disease is in the exterior, belonging to Taiyang disease, and sweating should be induced, thus Gui Zhi Tang is used. Article 43 states: In Taiyang disease, if after purging there is slight wheezing, the exterior has not resolved, Gui Zhi Jia Hou Po Xing Ren Tang (Cinnamon Twig Decoction with Magnolia Bark and Apricot Kernel) is the main treatment. Analysis: After using purging methods, if the cun pulse remains floating, it indicates the exterior has not resolved. Symptoms can include wheezing, coughing, or Qi rising. Article 45 states: In Taiyang disease, if sweating does not resolve the condition and purging is done again, if the pulse is floating, it will not recover. Floating indicates it is on the exterior, and purging again will not resolve it. Now, with a floating pulse, it indicates it is on the exterior, and one must release the exterior to recover, thus Gui Zhi Tang is used. Article 51 states: A floating pulse indicates the disease is in the exterior, and sweating can be induced; Ma Huang Tang is appropriate. Analysis: This article combines the original text of the Jin Gui Yao Lue, stating, “A floating pulse indicates the disease is in the exterior, and sweating can be induced; Ma Huang Tang is appropriate.” A floating cun pulse indicates the disease is in the exterior, and one should release the exterior. A strong floating pulse indicates Taiyang disease, while a weak floating pulse indicates Shaoyin disease. A floating chi pulse indicates the disease is in the interior, and treatment should be directed inward. A strong floating chi pulse indicates Yangming disease, while a weak floating chi pulse indicates Taiyin disease. A floating guan pulse indicates half exterior and half interior; a strong floating guan pulse indicates Shaoyang disease, while a weak floating guan pulse indicates Jueyin disease. Today, one must understand what a unique pulse is and what a floating pulse is. It is essential to know that a floating pulse is a type of unique pulse. The position of the floating pulse determines the different diagnoses of diseases. The same reasoning applies to a sinking pulse, which is also a unique pulse; if a patient has two floating pulses and one sinking pulse, it is a sinking pulse. For example: cun floating, guan floating, chi sinking is called chi sinking; cun sinking, guan floating, chi floating is called cun sinking; cun floating, guan sinking, chi floating is called guan sinking. The above three situations can all be referred to as sinking pulses. Article 266 states: If a Taiyang disease does not resolve and turns into Shaoyang, with hardness and fullness under the ribs, persistent vomiting, inability to eat, alternating Cold and Heat, and a sinking and tight pulse, Xiao Chai Hu Tang is the main treatment. Analysis: Here, the sinking and tight pulse refers to the guan pulse being sinking and tight, also known as unique guan pulse sinking and tight. Article 271 states: In cold damage for three days, if the Shaoyang pulse is small, it indicates a desire to resolve. Analysis: The Shaoyang pulse refers to the guan pulse. The Sage of Medicine determines the location of the disease based on the pulse position, unique pulse, and floating or sinking nature, and then prescribes treatment based on symptoms. This is the method of disease-pulse-symptom treatment.
