I. Research on the Kidneys

I. Research on the Kidneys

The kidneys are the foundation of innate constitution, the source of original yin and original yang. The yin and yang of all five viscera and six bowels are ultimately rooted in kidney yin and kidney yang. Throughout history, medical practitioners have attached great importance to the changes and transformations of kidney yin and kidney yang, considering them crucial issues related to human health, development, growth, aging, disease, and death.

In the 1950s, Shanghai First Medical College was the first to employ kidney-tonifying and yang-strengthening methods to treat six diseases—bronchial asthma, functional uterine bleeding, and others—that were considered completely different from a Western medical perspective, achieving satisfactory results and thereby revealing the essence of traditional TCM's "treating different diseases with the same method." Starting from this, extensive work was carried out to explore the nature of the kidneys, discovering that patients with kidney yang deficiency generally have lower-than-normal levels of 17-hydroxycorticosteroids in their 24-hour urine, indicating a connection between kidney yang deficiency and adrenal cortical function in modern medicine. Subsequently, plasma cortisol diurnal rhythm tests reflecting hypothalamic function, metyrapone SV-4884 tests reflecting pituitary function, and ACTH stimulation tests reflecting adrenal cortical function were adopted. Together, these three levels of testing provide a comprehensive view of the functional status of the hypothalamus-pituitary-adrenal cortex axis. Through these tests on individuals with kidney yin and kidney yang deficiencies, it was proven that patients with kidney yang deficiency exhibit dysfunction in the hypothalamus-pituitary-adrenal cortex axis, thus demonstrating that kidney yang deficiency has a material basis. After repeated experiments by scholars both domestically and internationally, a consistent view emerged: the TCM kidney is closely related to the modern endocrine system.

Since the 1980s, the Integrated Chinese-Western Medicine Research Institute of Shanghai First Medical College has expanded its research to include thyroid and gonadal axes, discovering that in patients with chronic bronchitis, those with kidney yang deficiency show normal T3 levels. In addition, a complete set of tests on the male gonadal axis was conducted on men with kidney yang deficiency and those with sexual dysfunction, revealing that patients with kidney yang deficiency exhibit varying degrees of gonadal axis dysfunction, whereas those with sexual dysfunction (without kidney yang deficiency symptoms) generally have normal gonadal axis function. Furthermore, tests on the thyroid and gonadal axes were conducted on elderly individuals averaging 69 years old, finding that their changes closely resemble those of patients with kidney yang deficiency. The appearance of kidney yang deficiency is positively correlated with aging, with the key factor being dysfunction in hypothalamic regulation. Thus, the exploration of the nature of kidney yang deficiency has gained a more precise meaning.

Guided by the above theories, domestic scholars have widely used kidney-tonifying and yang-strengthening medicines to treat aging, and experimental studies have demonstrated that these medicines can enhance T-cell immune function in the elderly. At the same time, kidney-tonifying and yang-strengthening medicines also have a significant anti-aging effect on the gonadal axis, thereby confirming the correctness of the statement that "the aging clock is the hypothalamus."

The Integrated Chinese-Western Medicine Research Institute of Shanghai First Medical College, following the traditional asthma treatment principle of "treat the lungs in emergencies, treat the kidneys in routine cases," formulated a kidney-tonifying and yang-strengthening tablet. A total of 419 asthma patients across seven batches received preventive kidney-tonifying treatment during the remission phase, with an effectiveness rate of 63.4% to 75.0%, compared to only 14% to 22.2% in the non-kidney-tonifying control group. Based on these results, endocrinological research was conducted, revealing that even asthma patients without clinical manifestations of kidney yang deficiency still exhibit potential changes in adrenal cortical function similar to those of kidney yang deficiency. The yang-strengthening tablet can adjust adrenal cortical function at the microscopic level and improve asthma attacks at the macroscopic level. In addition, the tablet also regulates the immune system and the neuroendocrine system, which may be another reason for preventing asthma attacks.

Traditional TCM holds that the kidneys store essence and govern reproduction; in men, the kidneys store essence, while in women, they are related to the uterus, indicating a close relationship between the kidneys and reproductive functions in both sexes. Shanghai First Medical College Obstetrics and Gynecology Hospital treats polycystic ovary syndrome, characterized by ovarian dysfunction and ovulation disorders, using kidney-tonifying and phlegm-resolving methods, achieving an effectiveness rate of 82.7%. To further explore the mechanism, a complete set of ovarian function tests was conducted on nine patients (vaginal smear erythrocyte count, urinary FSH bioassay, LRH stimulation test). The results confirmed that the true cause of ovarian dysfunction in these nine cases was hypothalamic dysfunction. Subsequently, nine additional patients underwent dynamic hormone level measurements for nine hormones, further confirming that the effect of kidney-tonifying and yang-strengthening medicines is a comprehensive action on multiple levels—hypothalamus, pituitary, and ovaries—rather than a single effect.

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Domestic studies have also observed the cardiac systolic time interval (STI) in patients with coronary heart disease complicated by heart qi deficiency syndrome, finding that these patients exhibit prolonged electromechanical systolic time (QS2), shortened left ventricular ejection time (LVET), prolonged pre-ejection period (PEP), and an increased PEP/LVET ratio, suggesting a close relationship between heart qi deficiency and left ventricular function. Based on the PEP/LVET ratio—the most sensitive and reliable indicator of left ventricular function—they set the upper limit of normal at 0.37; any value exceeding this threshold is considered indicative of abnormal left ventricular function. Statistical results show that the abnormal rate in the heart qi deficiency group of coronary heart disease is 94.7%, while in the heart qi and yin deficiency group it is 91.7%; no abnormalities were found among other patients with coronary heart disease.

In addition, some researchers used myocardial imaging to assess left ventricular function in patients with heart qi deficiency, confirming that such patients indeed suffer from left ventricular dysfunction. Other studies examined the left ventricular systolic time interval in 95 patients classified according to different syndrome differentiation patterns, concluding that cardiac dysfunction, reduced cardiac output, and insufficient blood perfusion to systemic tissues are the pathological basis for the development of heart qi deficiency.

V. Research on the Lung

The lung is regarded as the "crown" of the five zang organs and six fu organs. According to traditional Chinese medicine, the lung governs qi, controls respiration, is associated with the skin and hair, and has a superficial–deep relationship with the large intestine. From this perspective, the lung in TCM not only corresponds to the modern medical concept of the lung but also possesses functions that go beyond those of the modern lung. In addition to its respiratory function, the lung’s role in governing qi, its association with the skin and hair, and its connection with the large intestine are all key components of TCM’s organ theory. In recent years, some experimental research has been conducted to explore the underlying mechanisms of these concepts; although the findings are still preliminary, they do indicate that the functional aspects of the lung in TCM are grounded in physical reality.

1. The Lung and the Large Intestine: A Superficial–Deep Relationship

In recent years, domestic studies have investigated the superficial–deep relationship between the lung and the large intestine, consistently concluding that this traditional TCM theory has a material basis. First, it has been observed that severe intestinal dysfunction—such as various types of paralytic ileus, mechanical obstruction, and necrotizing enteritis—is often accompanied by respiratory failure. A classic example of concurrent intestinal and respiratory disorders is adult respiratory distress syndrome (ARDS). Modern medicine still struggles to fully explain why severe intestinal diseases can lead to respiratory complications. However, from the perspective of traditional TCM, the consensus across classical texts—from the Inner Canon and Difficult Classics to the Treatise on Cold Damage and Essential Prescriptions for Emergencies, as well as all subsequent medical works from the Tang and Song dynasties onward—regarding the relationship between the lung and the large intestine seems entirely logical. Clinical practice guided by this principle has repeatedly proven effective. To further elucidate the essence of this theory, domestic researchers conducted a systematic study involving 48 ARDS patients, finding that among them, 25 had pre-existing intestinal dysfunction prior to the onset of ARDS, while 23 did not. By “intestinal dysfunction,” we mean more than ordinary gastrointestinal disturbances. Of the 25 cases, 21 were paralytic ileus, 3 were mechanical obstruction, and 1 was mesenteric arterial embolism; 16 of these developed secondary toxic shock. All 25 patients with severe intestinal dysfunction suddenly developed acute respiratory failure 1–3 days after the onset of intestinal symptoms, characterized by rapid breathing—often exceeding 28 breaths per minute—decreased arterial oxygen partial pressure (PaO₂ < 8 kPa), increased A-aDO₂ (greater than 4 kPa during spontaneous breathing and greater than 13.3 kPa during pure oxygen administration), clearly demonstrating that severe intestinal dysfunction can impair lung function.

Building on these findings, some researchers created animal models by clamping the superior mesenteric artery to induce ischemic intestinal dysfunction, and discovered that the lungs of the same animals exhibited grade II or higher lesions, whereas the lungs of unclamped animals showed no such changes. At the same time, when equal numbers of animals were subjected to clamping of the renal artery or the lower limb arteries, no corresponding pulmonary changes were observed. Furthermore, comparing groups of animals where the superior mesenteric artery was clamped versus those where no arteries were clamped, the clamped group tested positive for endotoxins in their blood after 90 minutes of clamping, while the unclamped group remained negative for endotoxins even after 90 minutes of exposure to the superior mesenteric artery. These experiments demonstrate that intestinal dysfunction leads to pulmonary lesions, confirming the material basis of the TCM theory regarding the superficial–deep relationship between the lung and the large intestine. Preliminary evidence also suggests that this causal relationship may be linked to the production of endotoxins in the bloodstream.

Currently, in addition to the aforementioned experiments, some researchers have induced pulmonary lesions by creating permanent semi-ligation of the rectal ampulla, while others have refined the methods of clamping and permanent semi-ligation by using external ligation to produce reversible narrowing of the distal rectum, thereby triggering a series of pathological changes in the lungs. The results indicate that this improved model essentially achieves the intended purpose—namely, the induction of a series of pulmonary lesions. Beyond confirming the superficial–deep relationship between the lung and the large intestine, this model can be restored to normal by removing the external narrowing, thus enabling repeated use and providing better conditions for in-depth research into the theoretical underpinnings. Under the conditions of this modified animal model, artificially inducing dry stool retention in the colon results in the manifestation of Yangming腑实 syndrome, which in turn leads to specific pulmonary lesions. These lesions include pulmonary congestion, pulmonary hemorrhage, and pulmonary necrosis; electron microscopy reveals swelling and necrosis of the alveolar epithelium and macrophages, while other organs remain unaffected. Experiments suggest that administering Dachengqi Tang to the model animals significantly alleviates pulmonary symptoms.

2. The Lung Governs Qi

The significance of the TCM concept that the lung governs qi extends beyond its respiratory function to encompass other intrinsic functions of the lung itself; however, experimental research in this area remains limited. According to a report from the Pulmonary Function Research Laboratory of Zhejiang Provincial Hospital of Traditional Chinese Medicine, they selected pulmonary function tests—direct indicators that best reflect the role of lung qi—and conducted observations and studies focusing on the lung’s ventilation function. The results showed that in chronic obstructive pulmonary disease, patients with lung qi deficiency exhibited abnormal pulmonary function, whereas those without lung qi deficiency mostly maintained normal function, with only a few showing mild abnormalities. Statistical analysis revealed significant differences between the two groups. Among the abnormal cases, most patients in the lung qi deficiency group suffered moderate to severe ventilation impairment, predominantly of the mixed type, and the severity was markedly higher than in the non-deficient group. Many current literature reports consider closed lung volume, flow–volume curves, and lung compliance to be highly sensitive indicators for early diagnosis of small airway diseases. In TCM clinical practice, however, such diseases are often difficult to identify in their early stages, making the measurement of these indicators particularly important. These indicators increase in sensitivity in direct proportion to the degree of lung qi deficiency. The results obtained from 53 patients without lung qi deficiency in this study indicate that approximately half of them already exhibit microscopic changes indicative of lung qi imbalance. This suggests that the TCM concepts of lung qi and the lung’s governance of qi are grounded in physical reality, despite the limited number of experimental studies conducted so far. As future research in this area deepens, the true nature of TCM’s theory on the lung will inevitably be gradually revealed.

Section 5: Basic Principles of TCM Syndrome Differentiation and Treatment

Over nearly two millennia of development, traditional Chinese medicine has formulated a series of fundamental principles for syndrome differentiation and treatment through dialectical reasoning, symptom-based diagnosis, and etiological investigation. These include the Eight Principles, Zang-Fu differentiation, Six Meridians differentiation, Wei-Qi-Ying-Xue differentiation, Sanjiao differentiation, and Pathogenic Factor differentiation. These diagnostic frameworks serve as the main structure of TCM’s clinical syndrome differentiation and treatment theory, giving TCM its distinctive characteristics. When integrating Western and Eastern medicine and drawing on the strengths of both systems, it is essential to first emphasize the basic principles of TCM syndrome differentiation and treatment in order to highlight TCM’s unique advantages, such as its macroscopic, holistic, and organism-responsive perspectives.

I. Eight Principles of Syndrome Differentiation

The Eight Principles summarize clinical manifestations into eight categories: Yin, Yang, Exterior, Interior, Cold, Heat, Deficiency, and Excess. They represent the most fundamental diagnostic framework in TCM and serve as the guiding principle for classifying TCM syndromes. When faced with a complex array of symptoms, the key lies in identifying the core elements and organizing them systematically to determine appropriate treatment strategies and prescriptions—this can only be achieved by starting with the Eight Principles. TCM holds that any disease can be categorized using the Eight Principles: if the overall classification of the disease is not Yin, then it must be Yang; if the affected area is not on the surface, then it must be inside; if the nature of the disease is not Heat, then it must be Cold; and if the balance between pathogenic factors and vital energy is not Deficiency, then it must be Excess. Each of the Eight Principles has its own typical syndromes that can exist independently. At the same time, the four pairs of opposing syndromes within the Eight Principles exhibit an inseparable interrelationship. This means that if there is no Yin syndrome, there cannot be a Yang syndrome; if there is no Exterior syndrome, there cannot be an Interior syndrome; the concept of Cold syndrome is defined in opposition to Heat syndrome; and Deficiency and Excess are also relative terms. Clinically, multiple syndromes often coexist, with overlapping attributes—for example, Fuzi Lizhong Tang syndrome, which manifests as Interior Deficiency-Cold; Mahuang Tang syndrome, which manifests as Exterior Cold-Excess; Guizhi Tang syndrome, which manifests as Exterior Cold-Deficiency; and Chengqi Tang syndrome, which manifests as Interior Excess-Heat. The intricate and ever-changing progression of disease mechanisms—such as pathogenic factors moving from the exterior to the interior, then back to the exterior, alternating between Cold and Heat, and shifting between Deficiency and Excess—results in a wide variety of clinical presentations. Therefore, only by flexibly and skillfully applying the Eight Principles, accurately grasping the essence of the disease, and making a correct diagnosis can one provide a reliable basis for treatment. Among the Eight Principles, the Yin and Yang categories are particularly important, as they serve as the overarching framework for the other six categories. Yin governs Interior, Deficiency, and Cold, while Yang governs Exterior, Excess, and Heat. Any clinical manifestation of disease is ultimately the result of an imbalance between Yin and Yang; only by grounding oneself in the Yin and Yang categories can one gain a deeper understanding of Cold/Heat, Deficiency/Excess, and Exterior/Interior.