The Eight Principles (Ba Gang), which include Yin, Yang, Exterior, Interior, Cold, Heat, Deficiency, and Excess, form the theoretical foundation for learning differentiation and treatment in Traditional Chinese Medicine (TCM) and hold significant guiding importance in clinical diagnosis.
The Exterior and Interior principles help differentiate the location of diseases, whether they are internal or external, and the severity of the condition;
Cold and Heat principles help identify the nature of the disease;
Deficiency and Excess principles help differentiate the strength of pathogenic factors;
Yin and Yang serve as the overarching principles of the Eight Principles differentiation.
01Exterior and Interior Syndromes
Exterior syndromes are commonly seen in the early stages of externally contracted diseases, characterized by sudden onset and a short course of illness.
The clinical manifestations of exterior syndromes can be divided into primary and secondary symptoms.
Primary symptoms include fever and chills, body aches, thin white tongue coating, and floating pulse;
Secondary symptoms include nasal congestion with clear discharge, itchy throat, and cough.
Interior syndromes are often observed in the middle to later stages of externally contracted diseases or in cases of internal injury.
In addition to the symptoms of exterior syndromes, many other symptoms can be summarized as manifestations of interior syndromes.
Fever and chills occurring together, with little change in tongue coating, indicate an exterior syndrome;
However, if there is fever without chills or chills without fever, with significant changes in tongue coating and a deep pulse, this indicates an interior syndrome.
02Cold and Heat Syndromes
Cold syndromes are characterized by the invasion of cold pathogens or the dominance of Yin over Yang.
The clinical manifestations of cold syndromes can be summarized into five categories: cold (aversion to cold and preference for warmth), pale (pale complexion), thin (clear and thin phlegm, saliva, and nasal discharge), moist or pale (moist tongue), and quiet (slow pulse).
Heat syndromes are characterized by the invasion of heat pathogens or the dominance of Yang over Yin, leading to hyperactivity of bodily functions.
The clinical manifestations of heat syndromes can be summarized into five categories: heat (aversion to heat and preference for cold), yellow or red (short and red urine, yellow tongue coating), thick (thick phlegm and nasal discharge), dry (constipation, dry tongue coating), and restless (irritability).
Cold and heat syndromes are interconnected, exhibiting mixed cold and heat symptoms, transformation between cold and heat, and true versus false cold and heat.
The differentiation of true cold and false heat is both a key point and a challenge, often seen in critical illnesses.
True cold symptoms include cold extremities, clear and prolonged urination, thin stools, and a pale tongue with white coating;
False heat symptoms include body heat (but desiring to cover with blankets), a fluctuating red complexion (not as intense as true heat), thirst (but desiring warm drinks, drinking little, or even not wanting to swallow), throat pain (but not red or swollen), and a large pulse (but weak upon pressure).
True heat and false cold symptoms can also be divided into two groups:
True heat symptoms include dry throat and bad breath, preference for cold drinks, short and red urine, confusion, red tongue, and red or scorched lips;
False cold symptoms include cold body and cold extremities (but not desiring to cover), cold hands and feet (but with high body temperature and a hot abdomen), diarrhea (but with foul-smelling stools), black tongue coating (but dry and not moist), and a deep pulse (but strong upon pressure).
03Deficiency and Excess Syndromes
Deficiency syndromes are a pathological summary of various clinical manifestations characterized by weakness of the body’s vital energy, with features of insufficiency, relaxation, and decline.
The clinical manifestations of deficiency syndromes can be summarized into two categories: Yang deficiency and Yin-blood deficiency.
Excess syndromes are a pathological summary of various clinical manifestations characterized by the invasion of external pathogens or the accumulation of pathological products within the body, with features of excess, solidity, and strength.
The clinical manifestations of excess syndromes include symptoms such as phlegm accumulation, fluid retention, water retention, blood stasis, and parasitic accumulation.
Excess syndromes can be mixed with deficiency, deficiency can be mixed with excess, and both can be equally significant, leading to a complex interplay of deficiency and excess.
Due to the reflection of the struggle between pathogenic factors and the body’s vital energy, deficiency and excess can transform into one another, with true and false deficiency and excess being challenging content.
True deficiency and false excess manifestations include:
abdominal fullness (but sometimes alleviated, unlike the constant fullness of excess),
abdominal distension (but sometimes alleviated, unlike the constant distension of excess),
abdominal pain (but alleviated upon pressure), and a wiry pulse (but weak upon heavy pressure).
True excess and false deficiency manifestations include:
silent demeanor, not wanting to speak (but voice is loud and coarse),
fatigue (but feeling comfortable with slight movement),
diarrhea (but needing to relieve quickly), and a deep and thin pulse (but strong upon pressure).
Deficiency and excess can be distinguished based on characteristics, disease course, breath, pain, tongue, and pulse.
Characteristics: Deficiency syndromes exhibit signs of insufficiency, decline, and relaxation, while excess syndromes exhibit signs of excess, solidity, and strong sensations.
Disease course: Internal injuries from prolonged illness often belong to deficiency syndromes, while initial stages of external pathogens often belong to excess syndromes.
Breath: Deficiency syndromes have low and short breaths, while excess syndromes have loud and coarse breaths.
Pain: Deficiency syndromes prefer pressure, while excess syndromes resist pressure.
Tongue appearance: Deficiency syndromes have a plump and tender tongue, while excess syndromes have a dry and old appearance.
Pulse: Deficiency syndromes have weak pulses, while excess syndromes have strong pulses.
Yin and Yang Syndromes
Interior syndromes, deficiency syndromes, and cold syndromes generally belong to Yin syndromes;
Exterior syndromes, excess syndromes, and heat syndromes generally belong to Yang syndromes.
Yin deficiency and Yang deficiency are the two most common syndromes and should be mastered.
Yin deficiency is characterized by the loss of Yin fluids, leading to the emergence of false heat symptoms, with clinical manifestations including a series of symptoms related to insufficient Yin fluids and the internal generation of false heat.
Yang deficiency is characterized by the loss of Yang energy, leading to the emergence of false cold symptoms, with clinical manifestations including a series of symptoms related to Qi deficiency and cold signs.
In critical conditions, the differentiation of Yin and Yang syndromes should focus on the loss of Yin and loss of Yang.
Loss of Yin syndrome manifests as: sweating, heat sensation, salty taste, warm extremities, coarse breathing, thirst for cold drinks, red and dry face, thin and rapid pulse, and weak upon pressure.
Loss of Yang syndrome manifests as: cold sweating, bland taste, cold extremities, weak breathing, no thirst, preference for warm drinks, pale and moist tongue, thin and weak pulse, and floating and empty.
References
Practitioners emphasize “differentiation and treatment based on syndrome,” and each person’s “syndrome” is unique. The content provided in this public account is for discussion and learning purposes only and does not constitute medication advice. Please follow medical advice if needed.