Editing Traditional Chinese medicine (section)

====Eight principles of diagnosis====
The process of determining which actual pattern is on hand is called {{lang|zh|辩证}} ({{zh|labels=no|p=biàn zhèng}}, usually translated as "pattern diagnosis",<ref name="Ergil 2009" /> "pattern identification"<ref name="Wiseman 1996" /> or "pattern discrimination"<ref name="Flaws 1990" />). Generally, the first and most important step in pattern diagnosis is an evaluation of the present signs and symptoms on the basis of the "Eight Principles" ({{zh|c=八纲 |labels=no|p=bā gāng}}).<ref name="Ergil 2009" /><ref name="Wiseman 1996" /> These eight principles refer to four pairs of fundamental qualities of a disease: exterior/interior, heat/cold, vacuity/repletion, and yin/yang.<ref name="Wiseman 1996" /> Out of these, heat/cold and vacuity/repletion have the biggest clinical importance.<ref name="Wiseman 1996" /> The yin/yang quality, on the other side, has the smallest importance and is somewhat seen aside from the other three pairs, since it merely presents a general and vague conclusion regarding what other qualities are found.<ref name="Wiseman 1996" /> In detail, the Eight Principles refer to the following:
* ''Yin and yang'' are universal aspects all things can be classified under, this includes diseases in general as well as the Eight Principles' first three couples.<ref name="Wiseman 1996" /> For example, cold is identified to be a yin aspect, while heat is attributed to yang.<ref name="Wiseman 1996" /> Since descriptions of patterns in terms of yin and yang lack complexity and clinical practicality, though, patterns are usually not labeled this way anymore.<ref name="Wiseman 1996" /> Exceptions are vacuity-cold and repletion-heat patterns, who are sometimes referred to as "yin patterns" and "yang patterns" respectively.<ref name="Wiseman 1996" />
* ''Exterior'' ({{zh|c=表|labels=no|p=biǎo}}) refers to a disease manifesting in the superficial layers of the body – skin, hair, flesh, and meridians.<ref name="Wiseman 1996" /> It is characterized by aversion to cold and/or wind, headache, muscle ache, mild fever, a "floating" pulse, and a normal tongue appearance.<ref name="Wiseman 1996" />
* ''Interior'' ({{zh|c=里|labels=no|p=lǐ}}) refers to disease manifestation in the zàng-fǔ, or (in a wider sense) to any disease that can not be counted as exterior.<ref name="Deng 1999" /> There are no generalized characteristic symptoms of interior patterns, since they'll be determined by the affected zàng or fǔ entity.<ref name="Wiseman 1996" />
* ''Cold'' ({{zh|c=寒|labels=no|p=hán}}) is generally characterized by aversion to cold, absence of thirst, and a white tongue fur.<ref name="Wiseman 1996" /> More detailed characterization depends on whether cold is coupled with vacuity or repletion.<ref name="Wiseman 1996" />
* ''Heat'' ({{zh|c=热|labels=no|p=rè}}) is characterized by an absence of aversion to cold, a red and painful throat, a dry tongue fur and a rapid and floating pulse if it falls together with an exterior pattern.<ref name="Wiseman 1996" /> In all other cases, symptoms depend on whether heat is coupled with vacuity or repletion.<ref name="Wiseman 1996" />
* ''Deficiency'' ({{zh|c=虚|labels=no|p=xū}}), can be further differentiated into deficiency of [[#Qi|qi]], xuě, [[#Yin and yang|yin and yang]], with all their respective characteristic symptoms.<ref name="Wiseman 1996" /> Yin deficiency can also cause "empty-heat".<ref name="Kaptchuck 2000" />
* ''Excess'' ({{zh|c=实|labels=no|p=shí}}) generally refers to any disease that cannot be identified as a deficient pattern, and usually indicates the presence of one of the Six Excesses,<ref name="Deng 1999" /> or a pattern of stagnation (of qi, xuě, etc.).<ref name="hM4aY">Tierra & Tierra 1998, p. 108</ref> In a concurrent exterior pattern, excess is characterized by the absence of sweating.<ref name="Wiseman 1996" />

After the fundamental nature of a disease in terms of the Eight Principles is determined, the investigation focuses on more specific aspects.<ref name="Wiseman 1996" /> By evaluating the present signs and symptoms against the background of typical disharmony patterns of the various entities, evidence is collected whether or how specific entities are affected.<ref name="Wiseman 1996" /> This evaluation can be done
# in respect of the meridians ({{zh|c=经络辩证|labels=no|p=jīngluò biàn zhèng}})<ref name="Flaws 1990" />
# in respect of qi ({{zh|c=气血辩证, |labels=no|p=qì xuè biàn zhèng}})<ref name="Flaws 1990" />
# in respect of xuè ({{zh|c=气血辩证|labels=no|p=qì xuè biàn zhèng}})<ref name="Flaws 1990" />
# in respect of the body fluids ({{zh|c=津液辩证|labels=no|p= jīnyè biàn zhèng}})<ref name="Flaws 1990" />
# in respect of the zàng-fǔ ({{zh|c=脏腑辩证|labels=no|p= zàngfǔ biàn zhèng}})<ref name="Flaws 1990" /> – very similar to this, though less specific, is disharmony pattern description in terms of the Five Elements [{{zh|c=五行辩证|labels=no|p=wǔ xíng biàn zhèng}}]<ref name="Flaws 1996" />)

There are also three special pattern diagnosis systems used in case of febrile and infectious diseases only ("Six Channel system" or "six division pattern" &#91;{{zh|c=六经辩证|labels=no|p=liù jīng biàn zhèng}}&#93;; "Wei Qi Ying Xue system" or "four division pattern" [{{zh|c=卫气营血辩证|labels=no|p=weì qì yíng xuè biàn zhèng}}]; "San Jiao system" or "three burners pattern" &#91;{{zh|c=三焦辩证|labels=no|p=sānjiaō biàn zhèng}}&#93;).<ref name="Flaws 1996" /><ref name="Clavey 1995" />