Six-meridians syndrome differentiation, a method developed by Zhang Zhongjing, a celebrated doctor in the Han Dynasty, is the principle for syndrome differentiation and treatment in Treatise on Seasonal Febrile Disease and is the basis of syndrome differentiation for the later generations.
Six-meridians syndrome differentiation categorizes the stages of exogenous febrile diseases into six types for selection of treatment according to the main principle of yin and yang, namely taiyang disease, yangming disease, shaoyang disease, taiyin disease, shaoyin disease and jueyin disease.
Six-meridians diseases reflect the pathological changes of the meridians and viscera. Among the six types of diseases, taiyang disease pertains to the external, yangruing disease to the internal, shaoyang disease to the semi-external and semi-internal; while the three yin types all pertain to the internal. The three yang types of disease reflect the pathological changes of the six fu organs, while the three yin types of diseases reflect the pathological changes of the five zang organs. So the six-meridians diseases include the pathological changes of both the twelve meridians and viscera. Since the six-meridians syndrome differentiation focuses on the analysis of the pathological changes and transmission rule of diseases caused by exogenous wind-cold, they are not identical with syndrome differentiation of viscera.
Taiyang governs the superficies and controls both nutrient and defensive qi. When wind and cold attacks the human body, it first invades taiyang. Then defensive qi will take action to resist. The struggle between pathogenic factors and healthy qi in the superficies brings about taiyang meridian disease which reflects the primary stage of exogenous febrile disease. If the pathogenic factors are not relieved and enter the fu organs along the meridians,it will cause taiyang fu syndrome.
Taiyang meridian syndrome
Taiyang meridian syndrome, the disease caused by invasion of pathogenic factors into the superficies, may be divided into taiyang wind-attack syndrome and taiyang cold-attack syndrome according to the constitution of the patients and the nature of pathogenic factors.
Taiyang wind-attack syndrome: A syndrome caused by invasion of pathogenic wind into the superficies and disorder of nutrient and defensive qi.
Clinical manifestations：Fever, aversion to wind,sweating, stiffness and pain in the neck and head, whitish thin tongue fur and floating and slow pulse.
Analysis of the symptoms：Fever is caused by invasion of pathogenic wind into the superficies and struggle between defensive qi and pathogenic factors; sweating and aversion to wind are caused by looseness of the muscular interstices and failure of nutrient qi to keep inside because wind tends to open and disperse; stiffness and pain in the neck and head are caused by pathogenic wind attack and disorder of meridian qi because taiyang meridians converge over the head and distribute down to the neck from the head; whitish thin tongue fur is due to the fact that pathogenic factors are still retained in the skin and have penetrated inside; floating and slow pulse is the sign of external asthenia.
Taiyang cold-attack syndrome: The disease caused by invasion of pathogenic cold into the superficies, obstruction of defensive qi and stagnation of nutrient qi.
Clinical manifestations: Aversion to cold, fever, no sweating, or dyspnea, stiffness and pain in the neck and head, body pain, whitish thin tongue fur and floating and tense pulse.
Analysis of the symptoms: Aversion to cold is caused by cold attacking the superficies, and stagnation of defensive qi; fever is caused by struggle between defensive qi and healthy qi; no sweating and dyspnea are caused by obstruction of the muscular interstices and failure of the lung to disperse and descend; pain in the head and body is caused by stagnation of nutrient qi and inhibited flow of meridian qi; whitish thin tongue fur, floating and tense pulse are the signs of wind and cold attacking the superficies.
Taiyang fu syndrome
Taiyang fu syndrome refers to the syndrome due to failure to relieve taiyang meridian syndrome and transmission of pathogenic factors into the bladder along the meridians. It may be divided into taiyang water-accumulation syndrome and taiyang blood-accumulation syndrome according to the pathogenesis.
Taiyang water-accumulation syndrome: A syndrome caused by hypofunction of the bladder in transforming qi and accumulation and retention of water due to failure to relieve taiyang meridian syndrome and transmission of pathogenic factors into the bladder.
Clinical manifestations: Fever, aversion to cold, dysuria, lower abdominal distension and fullness, thirst, vomiting after drinking water and floating pulse.
Analysis of the symptoms: Fever, aversion to cold and floating pulse are caused by failure to relieve taiyang meridian syndrome; dysuria and lower abdominal distension and fullness are caused by transmission of pathogenic heat into the bladder and dysfunction of the bladder in transforming qi; thirst is due to retention of fluid and failure of qi to distribute fluid; vomiting after drinking is due to indigestion and adverse flow of gastric qi.
Taiyang blood-accumulation syndrome: This syndrome is caused by internal transmission of pathogenic factors and its mixture with blood in the lower energizer due to failure to relieve taiyang meridian syndrome.
Clinical manifestations: Lower abdominal spasm,fullness or mass, normal urination, mania, deep and un-smooth pulse or deep and knotted pulse.
Analysis of the symptoms:Lower abdominal spasm or even hard mass is due to improper treatment of taiyang meridian syndrome which leads to transmission of pathogenic heat into the internal and its mixture with blood in the lower abdomen; mania is caused by internal stagnation of heat disturbing mind; normal urination is due to the fact that the disease still remains in blood phase and has not affect the function of the bladder in transforming qi; deep and unsmooth or deep and knotted pulse is the sign of obstruction due to stagnation of heat and inhibited flow of blood.
Yangming syndrome, the syndrome due to invasion of pathogenic factors into yangming meridian, hyperactivity of yang heat and dry-heat in the stomach and intestines, is the critical stage during the course of struggle between pathogenic factors and healthy qi in exogenous febrile disease. Yangming syndrome is usually caused by delayed or improper treatment of taiyang disease which leads to pathogenic factors transmitting inside and transforming into heat; or by exogenous factors attack on people with frequent deficiency of body fluid and relative superabundance of yangqi. Yangming syndrome can be divided into yangming meridian syndrome and yangming fu syndrome according to the location of disease and the characteristics of syndrome.