病之经络、脏腑、营卫、气血、表里、阴阳、寒热、虚实。毕形于舌。故辨症以舌为主。而以
脉症兼参之。此要法也。兹将舌之部位形色。详列于左。实临症者之金鉴焉。
满舌属胃。中心亦属胃。舌尖属心。舌根属肾。两旁属肝胆。四畔属脾。
（又）舌尖属上脘。舌中属中脘。舌根属下脘。
白苔肺经。绛苔心经。黄苔胃经。鲜红胆经。黑苔脾经。紫色肾经。焦紫起刺肝经。青滑肝经。
白苔肺经。候卫分气分之表邪也。（肺属金故白苔应肺）
肺主卫。主气。主皮毛。风寒先入皮毛。内应乎肺。又太阳主一身之表。故肺家之邪。即可以候太阳
之表。仲景麻黄汤。亦泻肺分之邪也。舌无苔而润。或微白而薄者。风寒也。外症必恶寒发热。而口不渴。
宜温散之。舌苔白而燥刺者。温邪也。
邵评∶风寒在表。故无苔而薄白。
外症必微寒。继即发热不已。此伤在手太阴肺经。宜凉散之。忌足经辛温药。
舌白而粘腻者。湿邪在于气分也。外症必发热头重身痛。而口不渴。宜解肌去湿。如桂枝、秦艽、羌
活、紫苏、二陈、二苓之类。
邵评∶湿邪干犯气分。
肺分虽兼太阳。惟寒邪可用足经辛温药。若风温入肺。症见发热口渴。咳嗽喉
痛。舌苔白燥。或白兼边红。治宜轻清凉解肺经。如栀、豉、桑、杏、蒌皮、象贝、前胡、薄荷、苏子、
黄芩、桔梗之类。
邵评∶风温犯肺之正法。
绛苔心经。候营分血分之温热也。（心属火故绛色应心绛深红色）
心主营。主血。舌苔绛燥。邪已入营中。宜清络中之热。血分之火。忌用气分药。
凡温邪从口鼻吸入。上焦心肺先受。如舌苔先白后红者。邪先入气分。后入营分也。如初起舌即绛色者。
邪不入气分。而入营分也。宜清解营分之热。犀角、鲜生地、（北方无此）丹皮、元参之类。暑邪温疫。
如遇此苔。亦宜泄营解毒。凡白苔邪在气分。宜解表。忌清里。绛苔邪在营分。宜清热。忌发汗。经主气。
络主血。卫主气。营主血。临症最宜辨清。
黄苔胃经。辨阳明里症之热邪也。（阳明燥金从土化故黄色应胃）
邪入手经。以舌之绛白。分心营肺卫矣。邪入足经。又当以舌之黄白。分表里为治也。盖白苔主表。黄苔
主里。太阳主表。阳明主里。故黄苔专主阳明里症而言。
辨症之法。但看舌苔带一分白。病亦带一分表。必纯黄无白。邪方离表而入里。
邵评∶此以舌苔黄白。分邪之在表在里。
如见舌苔白中带黄。或微黄而薄。是邪初入阳明。犹带表症。微兼恶寒。宜凉散
之。如黄而兼燥。外症不恶寒。反恶热。是伤寒外邪。初入阳明之里。或温热内邪。欲出阳明之表。
斯时胃家。热而未实。宜栀豉白虎之类。清之可也。如浓黄燥刺。或边黄中心焦黑起刺。脐腹胀满硬痛。
乃阳明里症也。承气汤下之。
红色胆经 候少阳内发之温邪也。（少阳相火从火化故红色应胆）
少阳以木火为用。温邪内发。必借少阳为出路。乃同气之应也。如淡红嫩红。白中带红。是温邪之
轻者。初起微寒。即发热不已。口渴甚者。是也。宜柴、芩、栀、翘等清解之。如纯红。鲜红起刺。
此胆火炽。而营分热。急宜犀角、翘、丹等清解之。如不解。此温邪伏于少阴。而发于少阳之表也。
症匪轻渺。速宜重加鲜生地、麦冬、元参之类。以滋少阴之水。而少阳之火自解矣。大忌风药。
内伏之温邪。自少阴而从少阳发出。以救阴泄热为要。又风温瘟疫等症。如见舌苔鲜红者。当从手少阴治。
邵评∶从手厥阴心包络施治。即是治心。
黑苔脾经。辨太阴湿土之寒热也。（太阴湿土从湿化易云水就湿故黑苔应脾）
太阴湿土所主。而水就湿。故脾家见症。每每舌现黑色。如舌苔灰黑而滑者。
此寒水侮土。太阴中寒症也。外症腹痛吐利手足指冷。六脉沉细。宜理中汤主之。
邵评∶寒中之太阴脾。自宜温中为定法。
如杂症而现黑滑苔者。必是湿饮伤脾。宜温中和脾逐饮治之。
邵评∶寒湿水饮伤脾。自宜温中逐饮。
如白苔而兼带灰黑色。更兼粘腻浮滑者。此太阴在经之湿邪。是从雨雾中得之。宜解肌渗湿。
如五苓散加羌、防之类。
邵评∶湿入。太阴之表。故可解肌利湿。
如白带黑点。或兼黑纹而粘腻者。亦属太阴气分之湿。宜行湿和脾。如黄中带黑。而浮滑粘腻者。
是太阴湿热内结。宜利湿清热。
若黑而燥刺。是阳经注入太阴之热邪。宜清火解毒。兼阳明治。如屡清不解。腹
无痞满硬痛之症者。不可妄投承气。是胃中津液干涸。少阴肾水不支。宜大小甘露饮主之。
邵评前半条。阳经热邪注入太阴。而阳明胃热。宜兼阳明治而用清解。后半条。是胃中阴液枯涸。宜滋养而不可下。
如舌苔黑刺。大便秘结。脐腹硬满攻痛。此燥矢为患也。承气汤下之。仍从阳明治。若黑而坚敛。焦刺如荔枝形者。
乃阳亢阴竭。胃汁肾液俱涸也。不治。若诸书但以黑苔为肾气凌心水来克火。百无一治。庸有未验。
邵评∶此系肾阴胃液俱竭。热阳亢极。阴涸而死。故曰不治。不得已用大剂滋阴清热之法。药勿间断。希救万一。
又有以舌之五色分五脏。乃五行之。死法。不足以测伤寒之变。
紫色肾经。察少阴本脏之虚邪也。（少阴君火从火化故紫色应肾）
六经惟肾无实症。故仲景于少阴症中。揭出脉微细。但欲寐。为主病。示正气之虚也。如见舌形紫而干涩。口渴唇
燥。外见少阴症者。此肾阴不足。坎中水亏。宜壮水为主。六味饮一阴煎之类。如兼谵语神昏。又当从手少阴治。微清
痰火。如生地、丹参、茯苓、川贝、菖蒲、钩藤、天竺黄之类。如舌形胖嫩。而色淡红者。外
症必见躁扰不宁。六脉迟微。或动气内发。腹寒畏冷。或初起吐利。手足逆冷。或格阳躁狂。六脉洪数无根。
此肾气大亏。坎中火衰。宜益火之原。人参八味主之。
邵评∶肾阳衰而虚火上逆。治以补火壮水。与上条水亏不同。
如舌形紫燥。唇焦齿黑。二便俱秘。此为阴中兼阳。可兼阳明以治。犀角、地黄、甘露饮之类。
邵评∶肾水亏而阳明热。治以滋水清热。
凡舌形圆大胖嫩。皆属少阴虚症。
不拘伤寒杂证。如见舌色紫如猪肝。枯晦绝无津液者。此肾液已涸。不治。痢疾见此苔。胃阴已竭。必死。
伤寒更衣后。舌苔顿去。而见紫色如猪肝者。此元气下泄。胃阴已绝。不治。如舌苔去。而见淡红有神者佳。
邵评∶此肾胃阴液涸绝舌苔。
焦紫肝经。辨厥阴阳毒之危候也。（厥阴风木从火化故焦紫应肝）
凡舌苔焦紫起刺如杨梅状者。此阳邪热毒已及肝脏。险症也。大便秘者。急以更衣散下之。金汁、人中黄
之类大清大解之。
邵评∶热毒入于厥阴。阴伤阳陷。故危险。
凡舌苔肝胆部位。有红紫点者。肝脏伏毒也。大凶之症。急用犀角尖、人中黄透之解之。此阳毒。谓阳邪热盛
不解。其毒及于厥阴肝脏。非金匮所称阴阳毒也。乃热毒陷入至阴。
青滑肝经。辨厥阴阴毒之危症也。（肝属木故青色应肝）
凡舌苔青滑乃阴寒之象。急宜四逆吴萸辈温之。外症若见面青唇紫囊缩厥逆筋急直视等症者。厥阴败症也。不
治。凡舌苔焦紫如刺。厥阴热毒。难治。青滑厥阴寒邪。吴萸温之即愈。
邵评∶阴寒直中厥阴。阳气虚弱欲脱。故为败症。
The manifestations of diseases in the meridians, zang-fu organs, Ying-Wei (Nutritive and Defensive Qi), Qi and Blood, exterior and interior, Yin and Yang, cold and heat, and deficiency and excess are all fully displayed on the tongue. Therefore, syndrome differentiation primarily relies on observing the tongue, supplemented by a comprehensive analysis of pulse and symptoms. This is a crucial method. The following details the correspondence between tongue regions and organs, as well as their colors and shapes, serving as an essential reference for clinical practitioners.
The entire tongue corresponds to the Stomach. The center of the tongue also corresponds to the Stomach. The tip corresponds to the Heart. The root corresponds to the Kidney. The sides correspond to the Liver and Gallbladder. The periphery corresponds to the Spleen.
(Additionally) The tongue tip corresponds to the Upper Wan (Upper Epigastric region). The middle corresponds to the Middle Wan (Middle Epigastric region). The root corresponds to the Lower Wan (Lower Epigastric region).
White coating corresponds to the Lung Meridian. Crimson coating corresponds to the Heart Meridian. Yellow coating corresponds to the Stomach Meridian. Fresh red color corresponds to the Gallbladder Meridian. Black coating corresponds to the Spleen Meridian. Purple color corresponds to the Kidney Meridian. Scorched purple with prickles corresponds to the Liver Meridian. Cyan and slippery corresponds to the Liver Meridian.
A white coating on the Lung Meridian indicates exterior pathogens in the Wei (Defensive) and Qi levels. (Since the Lung belongs to Metal, a white coating corresponds to the Lung.)
The Lung governs Wei Qi, Qi, and the skin and hair. Wind-cold pathogens first invade the skin and hair, internally corresponding to the Lung. Furthermore, the Taiyang meridian governs the exterior of the body. Thus, pathogens in the Lung can be used to assess Taiyang exterior syndromes. Zhang Zhongjing's Mahuang Tang (Ephedra Decoction) is also used to drain pathogens from the Lung division. If the tongue has no coating but is moist, or is slightly white and thin, it indicates wind-cold. External symptoms must include aversion to cold and fever, without thirst. It is suitable for treatment with warming dispersal methods. If the white coating is dry and has prickles, it indicates warm pathogens.
Shao's Commentary: Wind-cold at the exterior results in no coating and a thin white appearance.
External symptoms must include slight aversion to cold, followed by persistent fever. This indicates disease in the Hand-Taiyin Lung Meridian, suitable for treatment with cooling dispersal methods. Avoid acrid-warm herbs of the Foot meridians.
If the white coating is sticky and greasy, dampness pathogens reside in the Qi level. External symptoms must include fever, heavy head, and body pain, without thirst. Treatment should employ muscle-releasing and dampness-resolving methods, such as Guizhi (Cinnamon Twig), Qinjiao (Rhizoma Gentianae), Qianghuo (Rhizoma Notopterygii), Zisu (Perilla Leaf), Erchen Tang (Two-Cured Decoction), and Erling (Poria and Polyporus).
Shao's Commentary: Dampness pathogens invading the Qi level.
Although the Lung division also involves the Taiyang meridian, acrid-warm herbs of the Foot meridians are only applicable for cold pathogens. If wind-warmth enters the Lung, presenting with fever, thirst, cough, and sore throat, with a white dry coating or white with red edges, treatment should use light, cool, and clearing methods for the Lung Meridian, such as Zhizi (Gardenia), Chidou (Soja Seed), Sangye (Mulberry Leaf), Xingren (Apricot Seed), Gualoupi (Trichosanthes Peel), Xiangbei (Fritillaria Thunbergii Bulb), Qianhu (Peucedani Radix), Bohe (Mentha Haplocalyx), Suzi (Perilla Fruit), Huangqin (Scutellaria Root), and Jiegeng (Platycodon Root).
Shao's Commentary: This is the standard method for treating wind-warmth attacking the Lung.
A crimson coating on the Heart Meridian indicates warm-heat pathogens in the Ying (Nutritive) and Blood levels. (Since the Heart belongs to Fire, a crimson color corresponds to the Heart; crimson is a deep red.)
The Heart governs Ying and Blood. A dry crimson coating indicates that pathogens have entered the Ying level. It is suitable to clear heat from the collaterals and fire in the Blood level, avoiding medications for the Qi level.
Generally, warm pathogens enter via the mouth and nose, affecting the Upper Jiao (Triple Burner) Heart and Lung first. If the coating turns from white to red, pathogens first enter the Qi level and then the Ying level. If the tongue is crimson from the onset, pathogens do not enter the Qi level but directly enter the Ying level. It is suitable to clear heat from the Ying level using Xijiao (Rhinoceros Horn - note: substitute with water buffalo horn in modern practice), Xianshengdi (Fresh Rehmannia Root), Mudanpi (Moutan Cortex), and Xuanshen (Scrophularia Root). For summerheat pathogens and warm epidemics, if this coating appears, one should also drain the Ying and resolve toxicity. Generally, for white coatings with pathogens in the Qi level, exterior release is indicated, while clearing the interior is contraindicated. For crimson coatings with pathogens in the Ying level, clearing heat is indicated, while sweating is contraindicated. Jing (Vessels) govern Qi, Luo (Collaterals) govern Blood; Wei (Defensive) governs Qi, Ying (Nutritive) governs Blood. These distinctions must be clearly identified during clinical practice.
A yellow coating on the Stomach Meridian identifies heat pathogens in Yangming interior syndromes. (Since Yangming Dry Metal transforms from Earth, a yellow color corresponds to the Stomach.)
When pathogens enter the Hand meridians, the crimson and white of the tongue distinguish between Heart-Ying and Lung-Wei. When pathogens enter the Foot meridians, the yellow and white of the tongue distinguish between exterior and interior for treatment. Generally, white coatings indicate the exterior, and yellow coatings indicate the interior. Taiyang governs the exterior, and Yangming governs the interior. Thus, yellow coatings specifically refer to Yangming interior syndromes.
The method of differentiation is as follows: if the coating retains any whiteness, the disease retains some exterior aspect. Only when it is purely yellow without any white does the pathogen leave the exterior and enter the interior.
Shao's Commentary: This uses the yellow and white of the tongue coating to distinguish whether pathogens are in the exterior or interior.
If the coating is white with yellow streaks, or slightly yellow and thin, it indicates pathogens have just entered Yangming, still carrying exterior symptoms with slight aversion to cold. Cooling dispersal is appropriate. If yellow and dry, with external symptoms of no aversion to cold but aversion to heat, this indicates cold pathogens from the exterior entering the Yangming interior, or internal warm pathogens attempting to exit through the Yangming exterior. At this stage, the Stomach is hot but not yet solidified. Zhi Chi Tang (Gardenia and Fermented Soybean Decoction) or Baihu Tang (White Tiger Decoction) may be used to clear heat. If the coating is thick yellow, dry, and prickle-like, or yellow on the edges with scorched black and prickles in the center, accompanied by abdominal distension, fullness, hardness, and pain, this is a Yangming interior syndrome, treated with Chengqi Tang (Downward-Pouring Decoction).
Red color corresponds to the Gallbladder Meridian, indicating endogenous warm pathogens in Shaoyang. (Since Shaoyang Ministerial Fire transforms from Fire, red color corresponds to the Gallbladder.)
Shaoyang utilizes Wood and Fire. Endogenous warm pathogens must use Shaoyang as an outlet, which is a response of similar energies. If the color is pale red or tender red, with white mixed with red, it indicates mild warm pathogens, starting with slight aversion to cold followed by persistent fever and severe thirst. Treatment with Chaihu (Bupleurum Root), Huangqin (Scutellaria Root), Zhizi (Gardenia), and Lianqiao (Forsythia Fruit) for clearing and resolving is appropriate. If pure red, fresh red with prickles, this indicates blazing Gallbladder fire and heat in the Ying level. Urgently treat with Xijiao (Rhinoceros Horn), Lianqiao (Forsythia Fruit), and Mudanpi (Moutan Cortex) for clearing and resolving. If unresolved, this indicates warm pathogens latent in Shaoyin, manifesting on the Shaoyang exterior. The condition is serious; urgently add generous amounts of Xianshengdi (Fresh Rehmannia Root), Maidong (Ophiopogon Tuber), and Xuanshen (Scrophularia Root) to nourish Shaoyin Water, so that Shaoyang Fire will naturally subside. Strongly avoid wind-dispelling herbs. Endogenous warm pathogens emerging from Shaoyin via Shaoyang require saving Yin and draining heat as the priority. Additionally, for wind-warmth and plague syndromes, if a fresh red tongue coating appears, treatment should follow the Hand-Shaoyin Heart Meridian.
Shao's Commentary: Treating via the Hand-Jueyin Pericardium Collateral is equivalent to treating the Heart.
Black coating corresponds to the Spleen Meridian, distinguishing cold and heat in Taoyin Damp Earth. (Since Taoyin Damp Earth transforms from Dampness, and "Water flows to dampness," black coating corresponds to the Spleen.)
Taoyin Damp Earth governs moisture, and water flows to dampness; thus, Spleen syndromes often present with a black tongue. If the coating is gray-black and slippery, this indicates Cold Water insulting Earth, a Taoyin Middle-Cold syndrome. External symptoms include abdominal pain, vomiting, diarrhea, cold extremities, and deep-thin pulses. Lizhong Tang (Regulate the Middle Decoction) is the primary treatment.
Shao's Commentary: For Taoyin Spleen affected by cold, warming the middle is the definitive method.
For miscellaneous diseases presenting with a black slippery coating, it must be damp-fluid injury to the Spleen. Treatment should involve warming the middle, harmonizing the Spleen, and expelling fluids.
Shao's Commentary: For cold-damp and fluid retention injuring the Spleen, warming the middle and expelling fluids is appropriate.
If a white coating is mixed with gray-black, especially if sticky, floating, and slippery, this is dampness in the Taoyin channels, contracted from rain and fog. Muscle-releasing and diaphoretic dampness-resolving methods are suitable, such as Wuling San (Five-Ingredient Powder with Poria) plus Qianghuo (Rhizoma Notopterygii) and Fangfeng (Saposhnikovia Root).
Shao's Commentary: Dampness entering the Taoyin exterior allows for muscle-releasing and dampness-draining.
If white with black spots, or black streaks with stickiness, it also belongs to dampness in the Taoyin Qi level. Promoting dampness movement and harmonizing the Spleen is appropriate. If yellow mixed with black, floating, slippery, and sticky, this is internal binding of Taoyin damp-heat. Draining dampness and clearing heat is appropriate.
If black and dry with prickles, it is heat pathogens injected from Yang meridians into Taoyin. Clearing fire and resolving toxicity, combined with Yangming treatment, is appropriate. If repeated clearing fails and there are no signs of abdominal痞 (fullness/hardness) or pain, do not recklessly administer Chengqi Tang. This indicates dried-up Stomach fluids and unsupported Shaoyin Kidney Water. Da Xiao Ganlu Yin (Great and Small Dew Drink) is appropriate.
Shao's Commentary First part: Heat pathogens from Yang meridians inject into Taoyin, and Yangming Stomach heat requires combined Yangming treatment with clearing and resolving. Second part: Stomach Yin fluids are withered; nourishment is required, not purging.
If the coating is black with prickles, constipation, and hard/full painful abdomen, this is caused by dry feces. Treat with Chengqi Tang (Downward-Pouring Decoction), still following Yangming treatment. If black, firm, constricted, with scorched prickles like a lychee, this indicates extreme Yang hyperactivity and Yin exhaustion, with both Stomach juices and Kidney fluids depleted. It is untreatable. Some texts merely attribute black coating to Kidney Qi overwhelming the Heart (Water overcoming Fire), claiming no cure; this is unverified by common experience.
Shao's Commentary: This is exhaustion of Kidney Yin and Stomach fluids, with extreme heat Yang and Yin depletion leading to death; hence termed untreatable. Desperately, large doses of Yin-nourishing and heat-clearing methods should be used continuously to hope for a miracle.
Using the five colors of the tongue to divide the Five Zang organs is a rigid application of Five Elements theory, insufficient for measuring the variations of Shanghan (Cold Damage).
Purple color corresponds to the Kidney Meridian, examining deficiency pathogens in the Shaoyin proper organ. (Since Shaoyin Sovereign Fire transforms from Fire, purple color corresponds to the Kidney.)
Among the Six Meridians, only the Kidney has no excess syndromes. Thus, Zhang Zhongjing highlights pulselessness/thinness and drowsiness as the main indicators in Shaoyin syndromes, showing deficiency of righteous Qi. If the tongue shape is purple, dry, and rough, with thirst and dry lips, alongside Shaoyin symptoms, this indicates Kidney Yin insufficiency and deficiency of Kan (Water) in the center. Treatment should focus on strengthening Water, using Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia) or Yiyin Jian (One-Yin Decoction). If accompanied by delirium and confusion, treat via the Hand-Shaoyin Heart Meridian, slightly clearing Phlegm-Fire with Shengdi (Rehmannia Root), Danshen (Salvia Root), Fuling (Poria), Chuanbeimu (Fritillaria Cirrhosa Bulb), Shichangpu (Acorus Rhizome), Gouteng (Uncaria Ramulus), and Tianzhuhuang (Calamus Tuber). If the tongue shape is fat and tender, with pale red color, external symptoms must include restlessness, slow/weak pulses, internal moving Qi, abdominal cold and fear of cold, initial vomiting/diarrhea, cold extremities, or false heat mania with surging-empty pulses. This indicates severe Kidney Qi deficiency and decline of Kan (Fire) in the center. Tonifying the source of Fire with Renshen Bawei Wan (Ginseng Eight-Ingredient Pill) is appropriate.
Shao's Commentary: Kidney Yang decline with defluxion of deficient fire is treated by tonifying Fire and strengthening Water, differing from the previous case of Water deficiency.
If the tongue is purple and dry, lips scorched, teeth black, and both urination and defecation blocked, this is Yin with concurrent Yang. Treat concurrently with Yangming using Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction) or Ganlu Yin (Dew Drink).
Shao's Commentary: Kidney Water deficiency with Yangming heat is treated by nourishing Water and clearing heat.
Any tongue shape that is round, large, fat, and tender belongs to Shaoyin deficiency syndromes.
Regardless of Shanghan or miscellaneous diseases, if the tongue color is purple like a pig's liver, withered, dull, and devoid of fluids, this indicates exhausted Kidney fluids; it is untreatable. In dysentery, this coating indicates exhausted Stomach Yin; death is certain. After defecation in Shanghan, if the coating suddenly disappears revealing a purple pig-liver color, this indicates downward leakage of Yuan Qi and absolute Stomach Yin exhaustion; it is untreatable. If the coating disappears revealing a pale red color with spirit/vitality, it is auspicious.
Shao's Commentary: This refers to the exhaustion of Kidney and Stomach Yin fluids causing tongue coating loss.
Scorched purple corresponds to the Liver Meridian, identifying critical conditions of Jueyin Yang Du (Yang Toxin). (Since Jueyin Wind-Wood transforms from Fire, scorched purple corresponds to the Liver.)
If the coating is scorched purple with prickles like a mulberry fruit, this indicates Yang pathogen heat-toxin has reached the Liver, a dangerous condition. With constipation, urgently purge with Gengyi San (Change Clothing Powder) and use Jinzhi (Gold Juice) or Renzhonghuang (Human Midden Yellow) for strong clearing and purging.
Shao's Commentary: Heat-toxin entering Jueyin causes Yin injury and Yang collapse, hence dangerous.
If red-purple spots appear in the Liver-Gallbladder areas of the tongue coating, this is latent toxin in the Liver, a highly ominous condition. Urgently use Xijiao Jian (Tip of Rhinoceros Horn) and Renzhonghuang (Human Midden Yellow) to penetrate and resolve. This is Yang Du, meaning unreleased excessive Yang pathogen heat whose toxin reaches the Jueyin Liver, distinct from the Yin-Yang Du mentioned in Jin Gui Yao Lue. It is heat-toxin sinking into the Extreme Yin.
Cyan and slippery corresponds to the Liver Meridian, identifying critical conditions of Jueyin Yin Du (Yin Toxin). (Since the Liver belongs to Wood, cyan color corresponds to the Liver.)
A cyan and slippery tongue coating is a sign of Yin cold. Urgently warm with Si Ni Tang (Counterflow Conqueror Decoction) and Wu Zhu Yu (Evodia Fruit). If external symptoms include cyan face, purple lips, retracted scrotum, reversal cold, tendon stiffness, and fixed gaze, this is a Jueyin failure syndrome; it is untreatable. Scorched purple with prickles indicates Jueyin heat-toxin, which is difficult to treat. Cyan slippery Jueyin cold pathogens are cured by warming with Wu Zhu Yu.
Shao's Commentary: Yin cold directly striking Jueyin with weak Yang Qi about to collapse constitutes a failure syndrome.