in the case of xuĕ; spleen qi vacuity, spleen yang vacuity, spleen qi vacuity with down-bearing qi, spleen qi vacuity with lack of blood containment, cold-damp invasion of the spleen, damp-heat invasion of spleen and stomach in case of the spleen zàng; wind/cold/damp invasion in the case of the meridians. tcm gives detailed prescriptions of these patterns regarding their typical symptoms, mostly including characteristic tongue and/or pulse findings. for example: "upflaming liver fire" (肝火上炎; gānhuǒ shàng yán): headache, red face, reddened eyes, dry mouth, nosebleeds, constipation, dry or hard stools, profuse menstruation, sudden tinnitus or deafness, vomiting of sour or bitter fluids, expectoration of blood, irascibility, impatience; red tongue with dry yellow fur; slippery and string-like pulse. eight principles of diagnosis the process of determining which actual pattern is on hand is called 辩证 (biàn zhèng, usually translated as "pattern diagnosis", "pattern identification" or "pattern discrimination"). 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" (八纲; bā gāng). these eight principles refer to four pairs of fundamental qualities of a disease: exterior/interior, heat/cold, vacuity/repletion, and yin/yang. out of these, heat/cold and vacuity/repletion have the biggest clinical importance. 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. 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. for example, cold is identified to be a yin aspect, while heat is attributed to yang. since descriptions of patterns in terms of yin and yang lack complexity and clinical practicality, though, patterns are usually not labeled this way anymore. exceptions are vacuity-cold and repletion-heat patterns, who are sometimes referred to as "yin patterns" and "yang patterns" respectively. exterior (表; biǎo) refers to a disease manifesting in the superficial layers of the body – skin, hair, flesh, and meridians. it is characterized by aversion to cold and/or wind, headache, muscle ache, mild fever, a "floating" pulse, and a normal tongue appearance. interior (里; lǐ) refers to disease manifestation in the zàng-fǔ, or (in a wider sense) to any disease that can not be counted as exterior. there are no generalized characteristic symptoms of interior patterns, since they'll be determined by the affected zàng or fǔ entity. cold (寒; hán) is generally characterized by aversion to cold, absence of thirst, and a white tongue fur. more detailed characterization depends on whether cold is coupled with vacuity or repletion. heat (热; 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. in all other cases, symptoms depend on whether heat is coupled with vacuity or repletion. deficiency (虚; xū), can be further differentiated into deficiency of qi, xuě, yin and yang, with all their respective characteristic symptoms. yin deficiency can also cause "empty-heat". excess (实; shí) generally refers to any disease that can't be identified as a deficient pattern, and usually indicates the presence of one of the six excesses, or a pattern of stagnation (of qi, xuě, etc.). in a concurrent exterior pattern, excess is characterized by the absence of sweating. after the fundamental nature of a disease in terms of the eight principles is determined, the investigation focuses on more specific aspects. 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. this evaluation can be done in respect of the meridians (经络辩证; jīngluò biàn zhèng) in respect of qi (气血辩证,; qì xuè biàn zhèng) in respect of xuè (气血辩证; qì xuè biàn zhèng) in respect of the body fluids (津液辩证; jīnyè biàn zhèng) in respect of the zàng-fǔ (脏腑辩证; zàngfǔ biàn zhèng) – very similar to this, though less specific, is disharmony pattern description in terms of the five elements ) there are also three special pattern diagnosis systems used in case of febrile and infectious diseases only ("six channel system" or "six division pattern" ; "wei qi ying xue system" or "four division pattern" ; "san jiao system" or "three burners pattern" ). considerations of disease causes although tcm and its concept of disease do not strongly differentiate between cause and effect, pattern discrimination can include considerations regarding the disease cause; this is called 病因辩证 (bìngyīn biàn zhèng, "disease-cause pattern discrimination"). there are three fundamental categories of disease causes (三因; sān yīn) recognized: external causes: these include the six excesses and "pestilential qi". internal causes: the "seven affects" (七情; qī qíng, sometimes also translated as "seven emotions") – joy, anger, brooding, sorrow, fear, fright and grief. these are believed to be able to cause damage to the functions of the zàng-fú, especially of the liver. non-external-non-internal causes: dietary irregularities (especially: too much raw, cold, spicy, fatty or sweet food; voracious eating; too much alcohol), fatigue, sexual intemperance, trauma, and parasites (虫; chóng). diagnostics in tcm, there are five major diagnostic methods: inspection, auscultation, olfaction, inquiry, and palpation. these are grouped into what is known as the "four pillars" of diagnosis, which are inspection, auscultation/ olfaction, inquiry, and palpation (望，聞，問，切). inspection focuses on the face and particularly on the tongue, including analysis of the tongue size, shape, tension, color and coating, and the absence or presence of teeth marks around the edge. auscultation refers to listening for particular sounds (such as wheezing). olfaction refers to attending to body odor. inquiry focuses on the "seven inquiries", which involve asking the person about the regularity, severity, or other characteristics of: chills, fever, perspiration, appetite, thirst, taste, defecation, urination, pain, sleep, menses, leukorrhea. palpation which includes feeling the body for tender a-shi points, and the palpation of the wrist pulses as well as various other pulses, and palpation of the abdomen. tongue and pulse examination of the tongue and the pulse are among the principal diagnostic methods in tcm. details of the tongue, including shape, size, color, texture, cracks, teeth marks, as well as tongue coating are all considered as part of tongue diagnosis. various regions of the tongue's surface are believed to correspond to the zàng-fŭ organs. for example, redness on the tip of the tongue might indicate heat in the heart, while redness on the sides of the tongue might indicate heat in the liver. pulse palpation involves measuring the pulse both at a superficial and at a deep level at three different locations on the radial artery (cun, guan, chi, located two fingerbreadths from the wrist crease, one fingerbreadth from the wrist crease, and right at the wrist crease, respectively, usually palpated with the index, middle and ring finger) of each arm, for a total of twelve pulses, all of which are thought to correspond with certain zàng-fŭ. the pulse is examined for several characteristics including rhythm, strength and volume, and described with qualities like "floating, slippery, bolstering-like, feeble, thready and quick"; each of these qualities indicates certain disease patterns. learning tcm pulse diagnosis can take several years. herbal medicine main article: chinese herbology assorted dried plant and animal parts used in traditional chinese medicines, clockwise from top left corner: dried lingzhi (lit. "spirit mushrooms"), ginseng, luo han guo, turtle shell underbelly (plastron), and dried curled snakes. chinese red ginseng roots a bile bear in a "crush cage" on huizhou farm, china. dried seahorses are extensively used in traditional medicine in china and elsewhere. the term "herbal medicine" is somewhat misleading in that, while plant elements are by far the most commonly used substances in tcm, other, non-botanic substances are used as well: animal, human, fungi, and mineral products are also used. thus, the term "medicinal" (instead of herb) may be used, although there is no scientific evidence that any of these compounds have medicinal effects. raw materials there are roughly 13,000 compounds used in china and over 100,000 tcm recipes recorded in the ancient literature. plant elements and extracts are by far the most common elements used. in the classic handbook of traditional drugs from 1941, 517 drugs were listed – out of these, 45 were animal parts, and 30 were minerals. animal substances animal bile is one of the common ingredients used in tcm, some include: dog, ox, common carp, mouse, python, goat, sheep, pig, chicken, elephant, bear, wild boar, shark, tiger, turtle, and more. through the anthropological and archaeological research of tcm, these biles were discovered to be part of the contents of the medicine and served different purposes in treating a variety of diseases. some animal parts used include cow gallstones, hornet nests, leeches, and scorpion. other examples of animal parts include horn of the antelope or buffalo, deer antlers, testicles and penis bone of the dog, and snake bile. some tcm textbooks still recommend preparations containing animal tissues, but there has been little research to justify the claimed clinical efficacy of many tcm animal products. some compounds can include the parts of endangered species, including tiger bones and rhinoceros horn which is used for many ailments (though not as an aphrodisiac as is commonly misunderstood in the west). the black market in rhinoceros horns (driven not just by tcm but also unrelated status-seeking) has reduced the world's rhino population by more than 90 percent over the past 40 years. concerns have also arisen over the use of pangolin scales, turtle plastron, seahorses, and the gill plates of mobula and manta rays. poachers hunt restricted or endangered species to supply the black market with tcm products. there is no scientific evidence of efficacy for tiger medicines. concern over china considering to legalize the trade in tiger parts prompted the 171-nation convention on international trade in endangered species (cites) to endorse a decision opposing the resurgence of trade in tigers. fewer than 30,000 saiga antelopes remain, which are exported to china for use in traditional fever therapies. organized gangs illegally export the horn of the antelopes to china. the pressures on seahorses (hippocampus spp.) used in traditional medicine is enormous; tens of millions of animals are unsustainably caught annually. many species of syngnathid are currently part of the iucn red list of threatened species or national equivalents. of all the animal biles, bear bile was the most valued in tcm, introduced after the han dynasty and before the sui dynasty. along with the bear bile, ox gallstones were recognized to have therapeutic use in tcm as well during the han dynasty. many tcm contains both bear bile and ox gallstones due to the chemical properties contained in them to aid in reversing health disorders. due to this, many ancient chinese physicians and pharmacists viewed the bear bile and ox gallstones to be "more precious than gold". this was discovered through the many written evidence from ancient chinese physicians and pharmacists on how to collect bear bile and ox gallstones. since tcm recognizes bear bile as a treatment compound, more than 12,000 asiatic black bears are held in bear farms. the bile is extracted through a permanent hole in the abdomen leading to the gall bladder, which can cause severe pain. this can lead to bears trying to kill themselves. as of 2012, approximately 10,000 bears are farmed in china for their bile. this practice has spurred public outcry across the country. the bile is collected from live bears via a surgical procedure. as of march 2020 bear bile as ingredient of tan re qing injection remains on the list of remedies recommended for treatment of "severe cases" of covid-19 by national health commission of china and the national administration of traditional chinese medicine. the deer penis is believed to have therapeutic benefits according to traditional chinese medicine. tiger parts from poached animals include tiger penis, believed to improve virility, and tiger eyes. the illegal trade for tiger parts in china has driven the species to near-extinction because of its popularity in traditional medicine. laws protecting even critically endangered species such as the sumatran tiger fail to stop the display and sale of these items in open markets. shark