“Deficiency and Excess Syndromes” are a pair of core principles in the Eight Principles of Differential Diagnosis in Traditional Chinese Medicine.
Simply put, a “Deficiency Syndrome” refers to a deficiency of the body’s vital energy (zhengqi) and a decline in organ function, such as qi deficiency, blood deficiency, yin deficiency, and yang deficiency; an “Excess Syndrome” refers to an excess of pathogenic factors and intense conflict between the body’s vital energy and pathogenic factors, such as phlegm-fluid retention, blood stasis, food stagnation, and invasion by external pathogenic factors. Distinguishing between deficiency and excess is the key basis for determining whether to adopt a treatment strategy that strengthens the body’s vital energy or expels pathogenic factors.
How to Distinguish Between Deficiency and Excess Syndromes
Disease Progression and Duration: New or sudden-onset illnesses are often excess; long-standing or chronic illnesses are often deficiency.
Constitution and Mental State: Excess syndromes are often characterized by a robust physique and restlessness; deficiency syndromes are often characterized by emaciation and listlessness.
Voice and Breathing: In excess patterns, the voice is loud and the breathing coarse; in deficiency patterns, the voice is low, the breathing weak, and the patient is short of breath and reluctant to speak.
Characteristics of Pain: In excess patterns, pain is aggravated by pressure; in deficiency patterns, pain is relieved by pressure.
Tongue and Pulse Manifestations: In excess patterns, the tongue coating is thick and greasy, and the pulse is full and forceful; in deficiency patterns, the tongue is pale with little coating, and the pulse is fine, weak, and lacking in force.
Common Complex Situations
Mixed Deficiency and Excess: A single patient may simultaneously exhibit both deficiency and excess patterns, such as spleen deficiency with dampness stagnation or pathogenic factors damaging the body’s vital energy. It is necessary to distinguish between primary and secondary factors and apply both purgative and tonifying treatments.
Transformation Between Deficiency and Excess: Prolonged excess patterns that damage the body’s vital energy may transform into deficiency patterns; conversely, dysfunction of the zang-fu organs due to deficiency may also lead to excess.
True Deficiency and False Deficiency: There are misleading manifestations such as “severe excess with signs of emaciation” (true excess masquerading as false deficiency) and “extreme deficiency with signs of excess” (true deficiency masquerading as false excess). These must be carefully distinguished; otherwise, one may easily fall into the trap of “mistaking deficiency for deficiency and excess for excess.”
A Story About Pulse Diagnosis
A while back, a young couple brought their child in for a consultation. After taking the child’s pulse, I told them that their child liked to sleep on their stomach at night. The parents nodded in agreement, while the other patients in the room were quite surprised: “You can tell that just by taking the pulse? That’s impossible! That’s way too mysterious!”
To allay the parents’ concerns and help the other patients better understand Traditional Chinese Medicine, I continued, “Your child’s left cun pulse is thin, soft, and weak, indicating a deficiency of qi and blood in the heart—this is a deficiency pattern. In cases of deficiency syndrome, applying pressure to the affected area brings relief. For example, when we have a stomachache, if covering and pressing on the area feels better, it’s a deficiency syndrome; if covering and pressing makes the pain worse and feels uncomfortable, it’s an excess syndrome. Your child has a deficiency of qi and blood in the heart. When sleeping on his stomach, the pressure on his chest makes him feel more comfortable, which is why he chooses this sleeping position.”
I continued, “Essentially, pulse diagnosis cannot directly reveal a person’s sleeping posture, but it can determine the deficiency or excess of the internal organs. By assessing this deficiency or excess, we can naturally infer many things—sometimes even identify unhealthy lifestyle habits!”
The patients around us laughed. “So that’s how it is!”
In the previous chapter, I mentioned that “herbs that promote the circulation of qi and blood have a draining nature, while those that inhibit this circulation have a tonifying nature.” In fact, if we consider the situation of a child sleeping on their stomach, from the heart’s perspective, this can also be seen as a form of tonification—it is an instinctive reaction of the body in response to a deficiency of qi and blood in the heart.
Yin and Yang, Exterior and Interior, Cold and Heat, and Deficiency and Excess are collectively known as the Eight Principles of Differential Diagnosis. An excess of pathogenic factors constitutes an “excess pattern,” while a decline in vital energy constitutes a “deficiency pattern.” By assessing the deficiency or excess state of the zang-fu organs—tonifying what is deficient and draining what is in excess—we can achieve therapeutic results. If one fails to distinguish between deficiency and excess and indiscriminately applies tonifying or draining treatments, it is easy to produce the opposite effect and aggravate the condition.
Clinically, determining whether a condition is deficient or excess is quite simple. For example, in a patient with a headache, if they cover the affected area with their hand, it indicates a deficiency pattern—this is a protective reaction. When the patient covers the area, the pain subsides, so treatment should employ tonifying methods; if the patient is afraid to touch the painful area, it indicates that pathogenic factors are strong, signifying an excess pattern, and treatment should employ purging methods.
Another example is a patient with low back pain: if the patient frequently pats the lower back with their hand—indicating pain primarily caused by kidney deficiency, characterized by a dull ache—and feels relief after patting, with the condition improving, treatment should lean toward tonification; if tapping the painful area with a finger intensifies the pain, this indicates a heavy presence of pathogenic factors, and treatment should lean toward purgation.
Furthermore, the relative prominence of pathogenic excess and constitutional deficiency varies across different stages of a disease. For example, in patients with kidney stones, the acute phase is primarily characterized by pathogenic excess; even light tapping on the lower back causes pain. After taking medications that drain dampness and promote urination, the symptoms may shift to predominantly aching lower back pain, and light tapping may actually provide relief. At this stage, the pathological presentation is primarily one of kidney deficiency, and treatment should incorporate methods to strengthen the body’s vital energy.
Another example is a woman with dysmenorrhea: if the pain is relieved by covering or pressing the lower abdomen with the hand, it is typically a deficiency pattern requiring treatment with warming and tonifying herbs; if the pain feels like a needle prick and is exacerbated by pressure, it is an excess pattern, and treatment should prioritize herbs that promote blood circulation and regulate menstruation.
Understanding deficiency and excess deepens one’s comprehension of the essence of disease.
Deficiency and excess can be observed through the patient’s movements and confirmed by pulse diagnosis. A pulse that lacks strength, feels soft to the touch, and is easily interrupted by light pressure is commonly seen in patients with qi deficiency; a pulse that is very fine, as thin as a thread, is commonly seen in patients with blood deficiency; a weak pulse with fewer than 60 beats per minute is commonly seen in patients with yang deficiency; a fine pulse accompanied by more than 90 beats per minute is commonly seen in patients with yin deficiency. The cun, guan, and chi positions on the left and right wrists correspond to different zang-fu organs, and the pulse pattern at each location reflects the qi, blood, yin, and yang of the corresponding organ. By assessing the pulse patterns at these different locations, one can determine the state of qi and blood in the zang-fu organs.
In daily life, we often encounter people who, while sleeping, feel as though they are awake yet are unable to make a sound or move their limbs. Not only that, but at this moment, the brain urgently seeks to fall asleep; the person inevitably drifts off, and their consciousness becomes hazy. However, driven by the instinctive desire to retain consciousness and the fear of this state, they desperately try to break free—yet are unable to get up because they cannot move. At this moment, a simple touch from someone else can instantly wake them, or even a slight movement of the head is enough to rouse the body. This is commonly known as a nightmare, colloquially referred to as “being pinned down by a ghost.”
Those who have experienced a nightmare retain a vivid memory of it; that sense of helplessness often leaves one feeling deeply unsettled. If it happens only occasionally, it’s not a big deal, but if it occurs every day, you’ll develop a fear of sleeping, hesitating to fall asleep for fear of not waking up again.
When patients with this condition seek treatment, doctors often don’t know where to begin. Some doctors attribute it to excessive anxiety, but anti-anxiety medications yield only mediocre results. In fact, by taking the patient’s pulse, one can determine that they often suffer from deficient heart yang, which falls under the category of deficiency syndrome. By using the Guizhi Jia Longgu Muli Decoction to harmonize yin and yang and balance the ying and wei qi, a cure can be achieved.
The Guizhi Jia Longgu Muli Decoction originates from the *Jin Gui Yao Lue* by Zhang Zhongjing, a renowned physician of the Han Dynasty. It contains several herbal ingredients, including cinnamon twig, peony root, fresh ginger, licorice, jujube, dragon bone, and oyster shell, and is primarily used to treat yin-yang deficiency in cases of consumptive disease, seminal emission in men, erotic dreams in women, spontaneous sweating, night sweats, and enuresis. Many seemingly strange ailments can be effectively treated by taking this formula.
Some elderly people consistently dream of people who have long since passed away every night; they have grown accustomed to this and sometimes even joke that they are about to pass away themselves. In fact, this is also a condition caused by deficient heart yang and an imbalance between yin and yang, which can be cured by taking the Cinnamon Twig Decoction with Dragon Bone and Oyster Shell.
There are also patients who frequently dream of members of the opposite sex and engage in sexual intercourse with them while sleeping at night. This occurs night after night; over time, their bodies gradually waste away. Using the Decoction of Cinnamon Twig with Dragon Bone and Oyster Shell as the primary formula, with appropriate modifications, can also provide a cure.
These so-called intractable and strange ailments are, in fact, all related to the heart. Since the heart houses the spirit, when the heart’s qi, blood, and yin-yang become deficient, the spirit of the heart becomes undernourished, leading to a variety of symptoms. Gui Zhi Decoction has the function of harmonizing yin and yang, while dragon bone and oyster shell have the effect of calming the soul and stabilizing the spirit. When combined, there is no need to worry about the spirit of the heart being disturbed or a host of miscellaneous diseases arising.
Our bodies are profoundly mysterious; they are not as simple as modern medicine currently portrays them to be. The deeper one delves into their study, the more complex they become.
Taoist philosophy states: “One gives rise to two; two gives rise to three; three gives rise to all things.” When studying human diseases from the perspective of “all things,” one’s line of thought becomes convoluted, and treatment may end up neglecting one aspect while focusing on another. However, if one views the issue from the perspective of “one,” the picture becomes very clear. Traditional Chinese Medicine (TCM) employs the Four Diagnostic Methods—observation, auscultation, inquiry, and palpation—to gather diagnostic data. By synthesizing this information, it deduces the pathological states of the five zang organs, thereby formulating the optimal treatment plan. This constitutes a comprehensive and exquisite theoretical system.
Those unfamiliar with TCM see only the final step—the diagnostic results and medication prescriptions—without a deep understanding of the significance behind these diagnoses. Consequently, when a doctor cures a patient through palpation and herbal medicine, they assume TCM relies on guesswork—that it’s merely a matter of luck.
When we were children, whenever we encountered something we didn’t understand, we loved to ask “why.” It was by resolving these countless “whys” that our knowledge gradually grew richer. As adults, when faced with things we don’t understand, many of us no longer ask “why.” Instead, we dismiss these questions in the simplest, most blunt way possible, labeling them as false, illusory, fabricated, or even deliberately obscure. This not only hinders our further learning but also shapes our worldview. This holds true for studying medicine—and for learning anything else, for that matter!
Now, let’s explore the principles of health and wellness through another short story: “A Story About Keeping Goldfish.”
