(1) Characteristics of Deep Pulse “Insufficient when lifted, excessive when pressed.” The sensation of a deep pulse under the fingers is that the pulse is not obvious when taken superficially, but becomes increasingly pronounced with medium and deep pressure. The phrase from the “Pulse Classic” describes it succinctly: “Insufficient when lifted, excessive when pressed.” The standard “insufficient when lifted” refers to the pressure being less than that of a normal person’s pulse when taken superficially; “pressed” refers to the finger’s pressure reaching a certain level close to the muscle layer, where there is a noticeable resistance felt under the fingers. Compared to a normal person, it is “excessive when pressed,” meaning that the pulse is more pronounced during deep palpation than in a normal person. However, there can also be a relative excess, where the pulse during deep palpation is stronger than during medium palpation but weaker than in a normal person. (2) Mechanism of Formation and Diagnostic Significance of Deep Pulse 1. Pathogenic Qi invading the internal organs (primarily interior), leading to stagnation of Qi or blood, or the suppression of Yin and Yang by pathogenic factors. Throughout history, pulse literature, including current TCM textbooks, generally considers deep pulse to indicate interior conditions; however, this is not entirely accurate. It can only be said that deep pulse is often associated with interior syndromes, but to claim that deep pulse exclusively indicates interior conditions is somewhat forced. When pathogenic Qi affects the surface, skin, hair, muscles, tendons, bones, and vessels, it indicates a superficial condition that is unlikely to threaten life. When pathogenic Qi affects the internal organs, it signifies that the pathogenic factors have penetrated deeply into the core of the body, potentially endangering life. The appearance of disease in the six fu organs indicates that the pathogenic factors have deeply invaded the body; if the five zang organs are affected, the pathogenic factors have penetrated very deeply. In fact, the righteous Qi is suppressed by the interior pathogenic Qi, and the struggle between the righteous and pathogenic Qi can also manifest as a deep pulse. The Qi of the internal organs, and even the Yin fluids, blood, and Yang of the organs, will rise to fight against the pathogenic Qi. This is akin to the defense of Leningrad during World War II, where hundreds of thousands fought fiercely in the core area. Therefore, at this time, the pulse reflects the battleground of Qi and blood at a deeper level, hence it appears more pronounced in deeper palpation. The term “deep” means “insufficient when lifted, excessive when pressed,” indicating that the pulse is not obvious when lightly palpated, becomes noticeable with medium pressure, and is even more pronounced with deep pressure. A standard deep pulse reflects the battleground of Qi and blood at a deeper level. However, “wherever the pathogenic Qi gathers, its Qi must be deficient,” and the outcome of the struggle between the righteous and pathogenic Qi will consume the righteous Qi, so a deep pulse that is stronger with heavier pressure is relatively rare in clinical practice. If the righteous Qi is slightly deficient, the pulse may appear weak with heavy pressure. Therefore, a typical deep pulse is insufficient when taken superficially, becomes obvious with medium pressure, and is also pronounced with deep pressure, but not necessarily more pronounced than with medium pressure. When pathogenic Qi deeply invades the internal organs and contends with the righteous Qi, this is what TCM refers to as an interior syndrome. Thus, in most cases, deep pulse indicating interior conditions is valid. 2. Deficiency and depletion of Qi, blood, Yin, or Yang. Clinically, deficiency syndromes often present with a deep pulse. Whether it is Qi deficiency, blood deficiency, Yin deficiency, or Yang deficiency, when the righteous Qi is deficient to a certain extent, even if it is a standard deficiency or just a slight deficiency, the pulse will present as deep. A deficient body lacks the driving force or physiological active substances to fill the pulse vessels, leading to a reduced amplitude of the pulse, which becomes hidden in the depths. Depletion and loss can also lead to a deep pulse. The Qi and blood of the human body primarily protect the internal organs, so individuals with Yin and Yang Qi and blood deficiency often have cold hands and feet in winter, as the Qi and blood prioritize protecting the internal organs and can only give up protecting the surface. However, only when the deficiency is severe will the righteous Qi float outward, known as “floating Yang deficiency.” The righteous Qi and Qi mechanism floating outward desire to escape. The so-called pathogenic Qi internally obstructs, and the righteous Qi externally escapes, which will lead to a floating pulse; while in cases of deficiency or mild depletion, the pulse generally presents as deep. Interior deficiency is also an interior syndrome, and the pulse will naturally be deep. 3. Pathogenic Qi (mainly referring to cold, dampness, phlegm, and stasis) obstructing the superficial layers of the Jueyin and Shaoyin, and even partially obstructing the Yangming, Shaoyang, and Taiyin layers, can also present as a deep pulse. This third point is derived from my family tradition and years of clinical experience, and many may have doubts about this. The main reason is that the current understanding of “exterior syndromes” is often limited to the clinical manifestations recorded in the “Treatise on Cold Damage” regarding Taiyang cold damage and wind syndrome, thus narrowing the concept and clinical significance of “exterior syndromes.” This is also one of the most important reasons why TCM has lost ground in treating acute diseases, as many diseases are treated without recognizing exterior syndromes, and it is not understood that exterior syndromes can also present as a deep pulse. The so-called “loss of the exterior” refers to missing the opportunity to treat the disease at the exterior level. For example, in the previous discussion of pulse irregularities, we cited a case of viral myocarditis. During treatment, even using Sangju Decoction with Huo Xiang, Yu Jin, or Shi Chang Pu, or adding a bit of Yuan Zhi, was much more effective than directly treating the “interior” with Western medicine. The reason many cases of myocarditis linger for years, even decades, is primarily because both TCM and Western medicine have lost sight of the “exterior.” This disease originates from the exterior affecting the lungs, leading to the lungs affecting the Sanjiao, which then affects the pericardium. Moreover, the exterior cold has not yet dissipated, and the exterior pathogenic factors remain, with symptoms such as cough and throat itch, indicating that the source lies in the exterior wind. If we do not use formulas like Sangju Decoction to resolve the exterior, it is a major error in treatment choice. The first principle of TCM treatment is to follow the situation and guide accordingly. First, viral myocarditis arises from the exterior; second, exterior cold and other exterior pathogenic factors become the source of this disease. From the perspective of Western medicine, the Coxsackie virus continues to proliferate in the respiratory tract, continuously harming the myocardium. Therefore, the primary task is to clear the respiratory tract to prevent the virus from surviving, allowing the myocardium to find peace. The disease’s progression is from the exterior to the interior, so our treatment must “address the source of the disease” and expel the pathogenic factors from the inside out; this momentum must not be mistaken. The reason patients continue to express symptoms such as cough, sneezing, runny nose, and fever is that the body’s non-specific immune response is fully expressed, indicating that the body is unwilling to let these pathogenic factors remain at the surface, thus they must be thoroughly eliminated. Although the current disease has transformed into viral myocarditis, the body still signals the doctor through cough, sneezing, and runny nose that the main battleground is still at the surface, and the righteous Qi is still fiercely contending to expel the pathogenic factors; the body is still experiencing fever, and the righteous Qi is at the surface, with Ying and Wei fighting against the pathogenic factors. Therefore, during treatment, we must use medication in accordance with the body’s momentum, guiding the treatment accordingly to achieve significant results. Additionally, understanding the progression of the disease requires us to comprehend its origins. This disease begins with an upper respiratory infection, and after a day or two, cough appears, followed by chest tightness and pulse irregularities. Although some cases may develop rapidly, with pulse irregularities appearing within two to three days, the initial onset of this disease is an exterior syndrome stemming from an upper respiratory infection, developing at varying speeds. Therefore, re-evaluating the classification of exterior syndrome symptoms is a clinical necessity. For instance, there are numerous reports in magazines about using Longdan Decoction to treat shingles, and while the treatment effect is indeed good, it takes a long time and is difficult to eradicate. The key issue lies in the “loss of the exterior.” The focus of using Longdan Decoction to treat shingles is that it can clear the damp-heat from the liver and gallbladder, but two important issues are overlooked: first, that 90% of the disease at its onset is fundamentally an exterior syndrome; second, that besides the limbs and superficial organs, the meridians are also considered exterior compared to the internal organs. The disease in the liver meridian does not entirely belong to the interior of the liver; the pathogenic factors in the meridians have not yet deeply penetrated the liver, so using Longdan Decoction to treat the superficial shingles pain can hardly be considered appropriate treatment, as it represents a “loss of the exterior.” I have achieved quick and effective results in treating shingles with herbs like Jin Yin Hua, Ku Ding Cha, and Qing Hao, which act on the exterior. There are many exterior syndromes in clinical practice, and the issue of “loss of the exterior” is prevalent in the treatment of diseases such as leukemia, systemic lupus erythematosus, cancer, cerebral palsy, and paraplegia. When patients come to me with fever, over 90% are afraid to get injections because they have become accustomed to the sweetness of Chinese medicine, which typically reduces fever within a day and a half. The key lies in my ability to identify exterior syndromes and address them. Therefore, exterior syndromes are a significant issue, and “loss of the exterior” is a major problem! What causes the “loss of the exterior”? The direct reason is that current textbooks do not even mention that “all six meridians have exterior syndromes,” thus misclassifying Ma Huang Fu Zi Xi Xin Decoction as a treatment for Tai Shao dual invasion, when in fact it is an exterior syndrome of Shaoyin. Otherwise, how could Ma Huang and Xi Xin be used to resolve the exterior? Furthermore, the issue of loss of the exterior also arises in clinical practice, as many exterior syndromes present with a deep pulse. For example, Zhang Zhongjing’s “Treatise on Cold Damage” clearly states in 300 cases: “In Shaoyin disease, if one initially has fever and the pulse is deep, Ma Huang Xi Xin Fu Zi Decoction is indicated.” Originally, fever is a symptom manifested at the surface, and Shaoyin disease is “initially acquired,” possibly lasting two to three days, so the pulse should be floating, especially with an exterior cold invasion. But why is there no resistance at the surface of the Taiyang? This is an abnormal phenomenon. Zhang Zhongjing used the term “反” (fan) here, indicating a “反沉” (reverse deep pulse), which is not a normal phenomenon. Zhang Zhongjing essentially states that most people’s righteous Qi is not so deficient that they cannot resist even a cold, nor can they produce nasal congestion or runny nose, or even a sneeze, or feel pain in their head or body. Instead, the pathogenic factors penetrate deeply, bypassing the Yang meridians and entering the Yin meridians, immediately presenting as a deep pulse, which is an abnormal phenomenon, a “反沉” (reverse deep pulse). This is a testament to our ancestor’s brilliance; any praise for scientists should be directed towards Zhang Zhongjing, who is a pride of our Chinese nation. For practical clinical needs, I have thought long and hard and concluded that the mechanism of deep pulse formation must include a third point. What does this mean? It means that while “deep pulse indicates interior conditions” is misleading to some extent, it is true that deep pulse generally reflects interior syndromes. However, we encounter deep pulses in exterior syndromes daily. As long as our patient numbers reach a certain level, and as long as people believe in us and come to us for seasonal and acute diseases, we can encounter deep pulses in exterior syndromes every day. Therefore, I have included the possibility of deep pulses in exterior syndromes into the mechanism of deep pulse formation, not to mention that classical texts have long acknowledged this. I once gave a lecture on “Taiyin Wind-Damp Exterior Syndrome” at the Guangdong Provincial Hospital of Traditional Chinese Medicine, where a typical clinical case involved a child with cerebral palsy who could not open his eyes, swallow, move his hands and feet, or turn over. I used methods to resolve the exterior, and at that time, almost everyone was puzzled. My diagnostic basis came from “Treatise on Cold Damage” 278: “In cold damage, if the pulse is floating and relaxed, and the hands and feet are warm, this indicates a connection to Taiyin.” Before my treatment, the fact was that the vast majority of doctors had lost sight of the “exterior” in the diagnosis and treatment of this disease. Due to misdiagnosis, the child experienced three instances of cardiac and respiratory arrest during treatment. The main reason for this was the misleading notion that “deep pulse indicates interior conditions.” If it is an exterior syndrome of Shaoyin or Jueyin, it is common for the pulse to be deep; almost all pulses are deep. However, since the Taiyin meridian is associated with the lungs, which govern the skin and hair, and the foot Taiyin meridian is associated with the spleen, which governs the muscles, the pulse can be both floating and deep. As long as there is a remnant of lung Qi and spleen Qi, as in the aforementioned child with cerebral palsy, once breathing and heartbeat are restored, the righteous Qi will contend with the pathogenic factors at the skin and muscle level, resulting in warm hands and feet. This is nature’s way of signaling to us, indicating that the patient is telling us: “You need to resolve the exterior for me!” You can see that the righteous Qi is fighting against the pathogenic factors at the body’s surface. We must not be like some who impersonate “God”; artificial cycles, artificial joints, and pig hearts replacing human hearts are not the main direction of medicine. Ultimately, medicine is about observation; we must carefully observe the body’s responses. If there are signs of contention between righteous and pathogenic Qi at the surface, we must resolve the exterior! Why does the pulse of Taiyin Wind-Damp Exterior Syndrome float? The lungs govern the skin and hair above, while the spleen governs the muscles. Therefore, the annotators of the “Treatise on Cold Damage” refer to Taiyin as “opening.” Theoretically, among the Yang meridians, Taiyang is “opening,” serving as the “barrier of the six meridians”; Yangming is “closing,” primarily governing the interior of the three Yang; Shaoyang governs the junction between exterior and interior, hence called “pivot.” Among the three Yin, Taiyin is “opening,” Shaoyin governs the interior as “closing,” and Jueyin governs the “pivot.” In clinical practice, this “opening” cannot be separated from the physiological and pathological aspects of the internal organs, as the lungs govern the upper and the skin, while the spleen governs the muscles. Therefore, the superficial tissues are closely related to them, so the pathogenic factors in Taiyin can present as both floating and deep pulses; while the Yangming primarily governs the interior, its exterior syndrome can also be deep, but floating pulses are more common, though deep pulses are not rare. Clinically, except for Taiyang exterior syndrome and Hand Taiyin lung wind-heat syndrome, other exterior syndromes can present with a deep pulse. This means that Taiyang exterior syndrome and Hand Taiyin lung wind-heat syndrome generally show floating pulses, while deep pulses are very rare; Foot Taiyin exterior syndrome can show both floating and deep pulses; Yangming exterior syndrome can also present with a deep pulse, but floating pulses are also quite common; other meridian exterior syndromes, especially Shaoyin and Jueyin exterior syndromes, almost always present with deep pulses, or at least not floating pulses. The three Yin meridians belong to the five zang organs. When the righteous Qi is not deficient, it is difficult for pathogenic Qi to penetrate directly into the three Yin. If pathogenic Qi can directly invade the three Yin, the patient often has a fundamental deficiency of righteous Qi. The aforementioned Taiyin exterior syndrome often occurs in individuals with insufficient spleen and lung Qi. The zang organs primarily store and do not leak, and the deficiency of the zang organs means that even in the case of three Yin exterior syndromes, due to insufficient organ Qi, they cannot contend with the pathogenic Qi at the surface, or the struggle between righteous and pathogenic Qi is not intense, making it difficult to see a floating pulse. Taiyin governs “opening,” and Taiyin wind-damp exterior syndrome can certainly present as a floating pulse, while Taiyin cold damage exterior syndrome can also present as a deep pulse. For example, in asthmatic patients with Yang deficiency, upon catching a cold, they may not even have time to sneeze or cough before they start wheezing, and they do not develop a fever at all. Modern medical scientists are clever, but their cleverness is limited. They can objectively describe the clinical manifestations of diseases: during an asthma attack, there is no fever; when exposed to cold or air conditioning, the patient starts wheezing, but why is there no fever? Why does it not present like pneumonia with fever? This is rarely discussed in Western medical literature, and even in TCM literature, it is seldom addressed, which is quite abnormal. The reason asthmatic patients with insufficient righteous Qi do not develop a fever during an attack is that the pathogenic Qi directly invades the three Yin. If the righteous Qi of the lungs, which governs the surface, is not deficient, it is difficult for pathogenic Qi to directly invade the three Yin. The mechanism of asthma attacks is primarily due to insufficient Wei Yang, insufficient lung Qi, and insufficient Yang to contend with cold pathogenic factors, making it impossible to fight against cold pathogenic factors at the surface, hence no fever occurs, unlike most patients with Ma Huang Decoction syndrome who experience fever, chills, headache, and body aches. “Diseases with fever and chills arise from Yang; those without fever and chills arise from Yin” (“Treatise on Cold Damage” 7). Therefore, these patients are cold without fever, especially in pediatric patients, where the deficiency of Yang is particularly evident, so we must cultivate their Yang. This means that if the factors suppressing Yang Qi are gradually eliminated through medication, and a little Yang Qi is supplemented, the patient’s body will gradually recover, and asthma will no longer occur. This is particularly evident in pediatric patients; once we eliminate the factors suppressing their Yang Qi, such as dampness, cold, and phlegm, their Yang Qi will gradually emerge. Eventually, before an asthma attack, when they catch a cold, the patient can even develop a fever, and we quickly say, “Congratulations!” If the fever reaches 40 degrees, it is a great joy. Fever is an important mechanism of resistance and a significant manifestation; when the fever subsides, asthma resolves. This originally mild disease, under the extensive use of antibiotics, hormones, and heat-clearing detoxifying herbs, suppresses the body’s Yang Qi, leading to bronchitis, further suppressing Yang Qi, resulting in dampness, cold, and even phlegm, leading to asthma. Many current cases of asthma may be iatrogenic diseases caused by this. As hospitals continue to grow, the number of patients will only increase. The foundation of TCM lies in clinical efficacy; if we do not “lose the exterior” and strive to improve our clinical level, we can reclaim many patients with acute diseases, even critical cases. Now, we must prepare for the post-antibiotic era. Antibiotics will inevitably become ineffective, and at that time, acute diseases will inevitably flow to TCM, and a significant portion of patients must be treated by TCM. This opportunity is set for those who are prepared. If a doctor is capable, there will be a continuous stream of patients, but the premise is to understand exterior syndromes and recognize that exterior syndromes can present as deep pulses, which will help eliminate many chronic and stubborn diseases at their source, leading to fewer illnesses in the world. Clinically, how do we determine exterior syndromes? The diagnostic criteria focus on three aspects: first, whether the patient’s symptoms and clinical manifestations emphasize the surface tissues, organs, and meridians; second, whether the patient has a history of exposure to external pathogenic factors, primarily including the six excesses of wind, cold, heat, dampness, dryness, fire, and epidemic Qi; third, whether the patient’s clinical manifestations do not show obvious interior symptoms. The so-called interior symptoms refer to the interior conditions described in “Treatise on Cold Damage” 252: “In cold damage, after six or seven days, if the eyes are unclear, the gaze is not harmonious, there are no exterior or interior symptoms, constipation, and slight fever, this is a solid condition. Urgent purging is indicated, and Da Chengqi Decoction should be used.” These are symptoms expressed by the organs, Qi, blood, and marrow, generally dominated by various organ symptoms. Exterior syndromes mostly occur at the onset, but can also persist for twenty to thirty years, with clinical manifestations primarily focused on Ying and Wei symptoms, with Wei symptoms mainly including chills, nasal congestion, and runny nose; Ying symptoms mainly include rashes, numbness, itching, pain, and redness and swelling of the skin surface. Except for Taiyang exterior syndrome and Hand Taiyin wind-heat syndrome, most other exterior syndromes can present with a deep pulse. In fact, Ma Huang Xi Xin Fu Zi Decoction is used to resolve exterior conditions in Shaoyin exterior syndrome. Judging solely by a deep pulse as Tai Shao dual invasion is insufficient; it must be combined with the presence or absence of interior symptoms for diagnosis. If there are no signs of Shaoyin interior syndrome, the diagnosis of Tai Shao dual invasion lacks basis. Misdiagnosis and mistreatment could lead to patient mortality. The true cold damage Tai Shao dual invasion appears in “Treatise on Cold Damage” 92: “In cold damage, if the physician purges and the patient continues to have clear diarrhea without stopping, and experiences body pain, urgent rescue of the interior is needed; if the body pain resolves and the bowel movements normalize, urgent rescue of the exterior is needed. For rescuing the interior, use Si Ni Decoction; for rescuing the exterior, use Gui Zhi Decoction.” Note that this is the true Tai Shao dual invasion! Zhang Zhongjing described its characteristics, and he wrote it very objectively. He stated that the patient has “clear diarrhea,” which refers to undigested food being expelled; the stool is very light in color, watery, and transparent. The nineteenth pathogenesis states that “clear and transparent belongs to cold.” Zhang Zhongjing believes that there is a Shaoyin deficiency-cold condition here. In addition to having a Shaoyin deficiency-cold condition, what else does the patient have? “Body pain” is indeed a clinical manifestation of an exterior syndrome, and Zhang Zhongjing confirms it as a clinical manifestation of an exterior syndrome, specifically a Taiyang exterior syndrome, similar to the body pain seen in Ma Huang Decoction, but the degree is not as severe. Therefore, Zhang Zhongjing believes that the appearance of the above symptoms indicates simultaneous disease in the Taiyang and Shaoyin. The dual invasion arises from later physicians referencing the content of the “Inner Canon,” stating that this is the simultaneous onset of Taiyang and Shaoyin, with both meridians simultaneously affected by cold pathogenic factors, which is called Tai Shao dual invasion. One of the basic characteristics of dual invasion is that “one cannot die within the expected time.” It does not lead to death within six days or after a complete cycle; the patient may die within two to three days. Tai Shao dual invasion is an acute critical condition; otherwise, Zhang Zhongjing would not have used the phrase “urgent rescue of the interior.” The primary treatment is to use Si Ni Decoction to save the patient’s life; otherwise, they will die. Secondly, it emphasizes that at this time, one must not resolve the exterior. Only if “the body pain resolves and the bowel movements normalize” can Gui Zhi Decoction be prescribed. Zhang Zhongjing established a strict treatment sequence here, but one must not be foolish. Why? Because the Taiyang interior is the Shaoyin; the patient has already suffered significant Yang deficiency, leading to deficiency-cold and clear diarrhea. If one resolves the Taiyang exterior, sweating could lead to the loss of Yang! We have learned many lessons from clinical practice. For example, I treated a 71-year-old diabetic man who had been using Da Mei Kang and Bai Tang Ping for a long time, leading to depletion of Yin essence, with a pulse that was wiry, thin, and hard, showing a trend of Yin depletion and significant Qi deficiency. Once, he caught a wind-heat cold and coughed, so I repeatedly advised against casually resolving the exterior, as he was on the verge of death. We previously discussed that “loss of the exterior” can be fatal, but at this time, resolving the exterior could also be fatal. There are many such examples, and the lessons are profound, including my mother, who passed away in this manner. She had emphysema and experienced six attacks within a few years, along with five instances of acute heart-related cerebral ischemia, known as A-S syndrome, due to heart failure and lack of oxygen. Each time she caught a cold, I advised relatives (some of whom are TCM practitioners) not to use Sangju Decoction lightly. Just two packets of Sangju Decoction would lead her into a coma, as my mother’s condition was a Tai Shao dual invasion. Originally, her Yang Qi was significantly deficient, and it was difficult to treat her back to a stable state. However, due to a flu infection from a caregiver, within half a day, she suddenly sneezed twice and had a runny nose. The hospital doctors used Ma Huang Xi Xin Fu Zi Decoction, and the next day she passed away. At this time, can we resolve the exterior? Can we use Ma Huang Xi Xin for Tai Shao dual invasion? That would certainly lead to death. The correct method is to first use Si Ni Decoction to completely stop the clear diarrhea, ensuring that the pulse no longer shows a deep and weak pattern, that the pulse has some degree of strength, and that she is willing to eat something before using Gui Zhi Decoction to harmonize, even if there is body pain, Ma Huang should not be used. It is also important to emphasize that Gui Zhi Decoction is not a sweating agent. Although Gui Zhi Decoction can treat Taiyang wind-cold with sweating, its primary function is to harmonize Ying and Wei. In fact, Gui Zhi Decoction has a slight effect of restraining sweating. At this time, even Gui Zhi Decoction should not be used, let alone Ma Huang or Xi Xin. Those who claim that Ma Huang Xi Xin Fu Zi Decoction treats Tai Shao dual invasion and include this content in textbooks are causing great harm. Ma Huang Xi Xin Fu Zi Decoction primarily treats cold pathogenic factors directly invading the Shaoyin exterior, presenting with fever, mild chills, no sweating, a deep pulse, or possibly weak or thin pulses, without headache, neck stiffness, or body pain. In miscellaneous diseases, it can present with lower back pain, occurring within two to three days. Shaoyin Yang Qi is insufficient, leading to mild deficiency, so cold pathogenic factors directly invade the Shaoyin exterior, and the body can still mobilize righteous Qi to contend with it, hence the pulse is deep but does not show weakness.
