Wang (inspection), wen (listening and smelling), wen( inquiry) and qie (taking pulse and palpation) are the four basic diagnostic methods used in TCM. In books like Huang Di Nei Jing (Yellow Emperor's Canon of Medicine), wang (inspection) and qie (taking pulse and palpation) were discussed theoretically in details.
Wang (inspection)--望
Inspection means to collect information about diseases through observing the patient. Inspection mainly refers to observation of the mental state, physical condition, facial expressions and tongue manifestations. To understand the internal through observing the external is an important method used to understand the physiological functions and pathological changes of the human body. Diagnosis made through observation is mainly based on the theory of wu xing (five elements). In the theory of wu xing (five elements), Fire matches with red and Metal matches with white. So red complexion indicates heat， while white complexion indicates cold. In terms of the internal organs, yellow color is related to the spleen and black color is related to the kidney. In terms of the orientations, the center corresponds to the spleen, the east corresponds to the liver and the west corresponds to the lung. So color over the left side of the cheekbone demonstrates the condition of the liver while color over the right side of the cheekbone demonstrates the condition of the lung. In inspection, luster is more important than color because luster indicates health while lusterlessness is a morbid state.
Inspection of the tongue is now a relatively independent diagnostic method. This method is mainly used to understand the condition of qi and blood. For instance, light-colored tongue means deficiency of blood while bulgy tongue indicates deficiency of qi. Through inspecting the tongue, one can understand the nature of pathogenic factors. For example, yellow tongue coating indicates heat, thick tongue coating shows severity of pathogenic factors and thick coating over the root of the tongue shows deeplocation of pathogenic factors.
The application of inspection is related to the theory of Channels. For instance, since ren mai (Conception Channel) runs along the front midline, beardless or even philtrum indicates insufficiency of qi in ren mai (Conception Channel) and problems in reproduction. According to experience, people have gradually reached the conclusion that those with long brows and large ears can enjoy a long life. Such empirical experience is also reflected in the theory of TCM. For instance, in TCM it believes that the brows reveal the condition of marrow while the ears demonstrate the condition of the kidney.
Qie (taking pulse or palpation)-切
This method is used to examine dislocation and fracture of bones, abdominal mass and skin condition. However it is most commonly used to examine the pulse conditions. The development of such a diagnostic method was based on the understanding of the pulsation of vessels in the body. That was why in ancient times this method was used to examine the pulsating points over several regions of the body. When the theory of Channels was established, such an examination was made over separated Channels.
To combine the pulse states with the diagnosis of diseases, doctors in the previous dynasties established various theories to guide the use of this method. TCM believes that the variation of the pulses is closely related to the fluctuation of yin and yang in the four seasons. That is why this method is also called pulse examination method in the four seasons. In the past pulse examination was used to examine the pulsations in the three regions of the body, namely the head, foot and hand (corresponding to the heaven, earth and human beings respectively). This way of pulse examination is known as three regions and nine divisions.
The method that is related to the commonly used pulse diagnosis method now is ren ying and cun kou examination. Ren ying is located in the cervical artery and pertains to yang while cun kou is located in the radial artery and pertains to yin. Now doctors just choose cun kou as the region to examine pulse. The pulse in cun kou is also divided into two parts, yin and yang, from the middle finger. The region one cun (about 3.3 cm) from the middle finger to the crease of wrist was known as cun while the region from the middle finger to the cubit was known as chi.
The changes of pulse examination, according to the present extant literature, can be traced back to the times Nan Jing (Canon on Eighty-One Difficult Issues). Nan ]ing (Canon on Eighty-One Difficult Issues) begins with a question: Why pulse examination is only done over the cun kou since all the twelve Channels have their own pulsations. Huang Di Nei ]ing (Yellow Emperor's Canon of Medicine) has mentioned examination of cubit, but it just means to examine the skin over the forearm. The changes of pulse examination in TCM were actually made on the basis of theory of yin-yang.
In the book entitled Mai Jing (Canon of Pulse) compiled by Wang Shuhe, an imperial doctor in the Western Jin Dynasty, another important change of pulse examination method took place. Guan, the point where the middle finger was put on in pulse examination, became another region for taking pulse. Then the pulse in cun kou was divided into three parts, cun, guan and chi, corresponding to the five zang-organs and sixfu-organs. The division of chi and cun then no longer correspond to yin and yang, but to the upper and lower portions of the human body. As to the correspondence of the pulses to the viscera, the cun, guan and chi on the left hand correspond to the heart, liver and kidney respectively; while the cun, guan and chi on the right hand correspond to the lung, spleen and ming men (gate oflife). Such an adjusted correspondence between pulses and viscera shows that yin and yang were replaced by left (yin, blood) and right (yang, qi). This method has been used till now. Mai Jing (Canon of Pulses) has mentioned 24 kinds of pulses. However in Huang Di Nei Jing (Yellow Emperor's Canon of Medicine), the pulses discussed are no more than ten kinds.
Wen (闻 listening and smelling) and Wen (问 inquiry)
Wen means to listen to the voices and breath as well as to smell the odors of the patient. This method is used to collect information for diagnosis and use of drugs. For instance, the sound of cough can help doctors understand the disease in question is due to dryness or wind invasion or phlegm or lung injury.
Inquiry is used by doctors both in TCM and Western medicine. Through inquiry, doctors can know the subjective feeling, living habit and anamnesis of the patient as well as the duration of disease. In the Ming Dynasty, Zhang Jingyue compiled Shi Wen Ge (A Poem of Ten Questions), summarizing the experience of previous doctors in inquiring patients in their clinical practice.These ten questions were improved and enriched by doctors of the later generations and eventually became the formula of inquiry.
Now various advanced modern technologies and instruments for diagnosis have been developed. So modern TCM doctors, apart from mastering the traditional techniques for diagnosis, have to be familiar with these new technologies and instruments and try to make use of them in their clinical diagnosis and treatment.
Only when synthetic analysis is made of the information collected with the four diagnostic methods can correct diagnosis be made. Such a synthetic analysis is known as differentiation of syndromes made according to the eight principles, namely yin, yang, interior, exterior, cold, heat, deficiency and excess.
Among these eight principles, yin and yang are the most important ones.
Pathological conditions are often complicated. Thus to make an accurate diagnosis is not always easy. Sometimes clinical manifestations may be false. So doctors have to carefully analyze the information collected with these four traditional diagnostic methods. Take pulmonary disorder in circulation due to right heart failure and leading to pneumonia for example. The methods of clearing away heat and removing toxin for dealing with common cold and pneumonia will be infective because the manifestation of heat is false. Only when large dosage of cardiac stimulant is used can inflammation be subdued and fever be relieved.
