经曰∶能合色脉，可以万全。舌尤色之易见者。昔张仲景着《伤寒论》及《金匮要略》
，皆
详舌胎，后人《伤寒舌鉴》，《脉理正义》，皆本此而推展之。惟杜清碧《验证舌法》，尤
为简明。盖舌为心窍，脏腑有病，必见之于舌。目病本于脏腑，故宜合舌胎以辨之。惟外感
有之，而内伤绝少。凡症初起，舌有白胎薄而淡者，是寒邪初入太阳也。白屑满舌，邪将传
入阳明也。白胎干浓者，此太阳热病也。白胎兼滑者，此太阳阳明并病也。白胎而中有微黄
者，此太阳之邪渐入阳明也。如表未罢，双解之，表已罢，下之。如作泻，清之导之。白胎
而尖微有刺者，此少阳阳明也。白胎而中有黑点者，亦少阳阳明也。如表未罢者，和解之。
表已罢，微下之。白胎而满黑刺者，此三阳合病也。白胎在左，阳明虚热也。白胎在右，少
阳受邪也。白胎而腻滑者，痰也。舌无白胎，外症厥冷者，寒中少阴也。白胎或左或右，而
余见黄黑，外证下利，痛引小腹者，脏结也，热甚者下之，无热者温之。白胎在尖红者，少
阳也。舌胎根白而尖者，太阳少阳并病也。舌白无胎而明淡，外症热者，胃虚也。凡舌无胎
垢而色变者，皆属虚也。白胎浓如积粉者，此瘟疫初犯膜原也。白胎而尖根俱黑，乃金水太
过，火土气绝于内，虽无凶证，亦必死也。白胎中见黑色两条，乃太阳少阳之邪入于胃，因
土气衰绝，故胸中结痛也。白胎中见灰色两条，乃夹冷食舌也。舌见微黄胎者，邪入阳明，
里热症也。次见深黄者，热渐甚也。再见干黄焦黄者，热愈亢也，宜下之。舌胎根黄而尖白
者，表少里多也。黄胎而滑者，阳明湿热也。黄胎而上有隔瓣者，邪毒甚深，急下之。黄胎
双垂夹见者，正阳阳明也。黄胎而中有斑者，将发斑也。无斑者，专下之。黄胎而中有刺者
，胃热甚也。黄胎而中有小黑点者，邪将入脏也，急下之。黄胎久而变黑，干燥生刺者，实
热亢极之候，不治者多。若遇此症，必须掘开舌胎，视瓣底红者，可急下之，瓣底黑者，不
治。舌胎中心黑浓而干者，为热盛津枯之候，舌中黑无胎而燥，津液受伤，虚火用事也。舌
黑有津边红，证见谵语者，虚人攻补兼用之，壮实者，急下之。夏月中 ，多有此舌，以辛
凉解之，间有大虚之候，须合脉症参之。中黑边白而滑者，表里俱虚寒也。凡舌胎纯黑者有
两症，一为火极似水，一为水来克火，其辨法火亢盛者，胎浓而多刺，水来克者，胎薄而无
刺。若舌黑中烂者，不治。舌至干黑而短者，不治。产后舌紫黑者，不治。凡见黑色，须问
曾食酸物，及甜咸物否，以其能染成黑色，非因病而生，故润而不燥，刮之即退也。若舌胎
见灰色，即黑色之轻者，与黑同治，亦有阴阳之分。如直中阴经者，实时舌变灰黑，而无积
胎，如传经热症，则灰黑干胎。大抵舌上黄白黑俱有胎，红紫则有色而无胎也。舌见纯红者
，乃火亢之极，瘟疫将深之象也。舌中心见红者，此太阳症也。舌红而尖起紫泡者，此心经
热毒也。舌红而中见紫斑者，将发斑也。舌淡红而中见红赤点者，将发黄也。舌红而碎裂如
人字纹者，此阳明传热于少阴心也。舌淡红而碎裂如川字纹者，此心经积热也。舌红而有刺
者，此胃有热积也。舌红而内有黑纹数条者，乃阴毒结于肝经，肝主筋，故舌见筋丝也。舌
红而有重舌者，此热毒入心胞，舌红而胀大满口，此热毒入于少阳阳明，均宜刺出恶血。舌
红而出血如衄，此热伤心胞也，宜凉血止血。舌红而硬强失音者，死候也，有痰者导之，内
实者下之，间有生者。舌红而碎烂如虫蚀者，此少阴瘟毒也，下之。舌红而吐弄者，此热在
心脾也。舌红而战动难言，舌红而痿软不能言者，皆心脾虚极也，多用人参可救。舌红而干
瘪者死，不治。舌见纯紫色者，此酒毒也。舌紫而中心带白者，酒毒在少阳也。舌紫而中心
带赤者，酒毒在阳明也。舌淡红而中见紫黑筋数道者，此厥阴真寒症也。据此论治，可以辨
虚实，别死生矣。
经典医籍说：能够结合面色与脉象进行诊断，治疗就可以万无一失。舌苔是观察面色（气色）最容易看到的部分。从前张仲景撰写《伤寒论》和《金匮要略》，都详细论述了舌苔，后世的《伤寒舌鉴》、《脉理正义》等书，都是基于此而进一步推演发展的。只有杜清碧的《验证舌法》，尤为简明扼要。因为舌为心之窍，脏腑若有疾病，必然反映在舌头上。眼病本源于脏腑，所以应当结合舌苔来辨别病情。这种舌诊方法主要适用于外感病，而内伤病极少见到。
凡是病症初起，舌苔白而薄且淡的，这是寒邪刚刚侵入太阳经。舌面布满白色苔垢如屑状，说明邪气将要传入阳明经。舌苔白而干厚的，这是太阳经的热病。舌苔白而兼滑的，这是太阳与阳明合病。舌苔白而中间微现黄色的，这是太阳经的邪气逐渐传入阳明经。如果表证未解，应用双解法；如果表证已解，应用攻下法。如果出现腹泻症状，应用清热导滞法。舌苔白而舌尖微有刺状的，这是少阳与阳明合病。舌苔白而中间有黑点的，也是少阳与阳明合病。如果表证未解，应用和解法；表证已解，应用轻微攻下法。舌苔白而满布黑色刺状的，这是三阳合病。舌苔白在左侧，是阳明经虚热；舌苔白在右侧，是少阳经受邪。舌苔白而腻滑的，是痰湿所致。
舌面无白苔，外部症状出现四肢厥冷的，是寒邪直中少阴经。舌苔白或偏左或偏右，其余部分呈现黄黑色，外部症状有下利、疼痛牵引小腹的，这是脏结证。热势严重的用攻下法，无热的用温补法。舌苔白而舌尖红的，属少阳经病变。舌苔根部白而舌尖红的，是太阳与少阳并病。舌色白而无苔垢且明净淡然的，外部症状有发热的，是胃气虚弱。凡是舌面无苔垢而颜色发生变化的，都属于虚证。舌苔白而浓厚如积粉的，这是瘟疫初犯膜原。舌苔白而舌尖和舌根都变黑，这是金水之气太过，火土之气在内衰竭，虽然表面上没有凶险症状，但也必定死亡。舌苔白中间出现两条黑色的，这是太阳、少阳的邪气入于胃，因为土气衰绝，所以胸中结聚疼痛。舌苔白中间出现两条灰色的，这是夹杂冷食的舌象。
舌见微黄苔的，是邪气入阳明，属于里热证。接着见到深黄苔的，是热势逐渐加重。再见到干黄、焦黄苔的，是热势更加亢盛，应当用攻下法。舌苔根部黄而舌尖白的，是表证轻里证重。黄苔而滑的，是阳明湿热。黄苔而上部有隔瓣的，是邪毒很深，必须急下。黄苔双重垂夹出现的，是正阳阳明证。黄苔中间有斑点的，是将要发斑疹。如果没有斑点，专门用攻下法。黄苔中间有刺状的，是胃热严重。黄苔中间有小黑点的，是邪气将要入脏，必须急下。黄苔久了变成黑色，干燥生刺的，是实热亢极的表现，不治的多。如果遇到这种情况，必须刮开舌苔，看瓣底红色的，可以急下；瓣底黑色的，不治。
舌苔中心黑而浓厚干燥的，是热盛津液枯竭的表现。舌中黑而无苔且燥的，是津液受伤，虚火作祟。舌黑而有津液、边缘红的，症状出现谵语的，体虚的人攻补兼用，体质壮实的，急下。夏季中暑，多有这种舌象，用辛凉法解除，间或有极度虚弱的情况，必须结合脉象和症状参详。舌中黑边白而滑的，是表里俱虚寒。凡是舌苔纯黑的有两种病症，一是火极似水，二是水来克火。其辨别方法是：火亢盛的，苔浓且有刺；水来克的，苔薄而无刺。如果舌黑中间腐烂的，不治。舌干枯黑而短的，不治。产后舌紫黑的，不治。凡是见到黑色，必须询问是否曾吃过酸性食物，以及甜咸食物，因为它们能染成黑色，并非因病而生，所以湿润而不干燥，刮之即退。
如果舌苔见灰色，就是黑色的轻者，治疗原则与黑色相同，也有阴阳之分。如果是直中阴经的，立刻舌变灰黑，而没有积苔；如果是传经热症，则是灰黑干苔。大抵舌上黄、白、黑都有苔，红、紫则是有色而无苔。舌见纯红的，是火亢极，瘟疫将深入的征象。舌中心见红的，这是太阳证。舌红而舌尖起紫泡的，这是心经热毒。舌红而中间见紫斑的，将要发斑疹。舌淡红而中间见红赤点的，将要发黄。舌红而碎裂如人字纹的，这是阳明传热于少阴心经。舌淡红而碎裂如川字纹的，这是心经积热。舌红而有刺的，这是胃有热积。舌红而内有黑纹数条的，是阴毒结于肝经，肝主筋，所以舌见筋丝。舌红而有重舌的，这是热毒入心包络；舌红而胀大满口，这是热毒入于少阳、阳明，均宜刺出恶血。舌红而出血如鼻衄的，这是热伤心包络，宜凉血止血。舌红而硬强失音的，是死候，有痰的用导法，内实用下法，间或有生还的。舌红而碎烂如虫蚀的，这是少阴瘟毒，用下法。舌红而吐弄的，这是热在心脾。舌红而战动难言，舌红而痿软不能言的，都是心脾虚极，多用人参可以救治。舌红而干瘪的，死，不治。舌见纯紫色的，这是酒毒。舌紫而中心带白的，酒毒在少阳。舌紫而中心带赤的，酒毒在阳明。舌淡红而中间见紫黑筋数道的，这是厥阴真寒证。根据这些理论来治疗，就可以辨别虚实，区分生死。
The classic texts state: "If one can combine the observation of complexion and pulse, treatment can be perfect." The tongue coating is the most easily observable aspect of the complexion (Qi color). In ancient times, Zhang Zhongjing wrote *Shanghan Lun* (Treatise on Cold Damage) and *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet), both detailing tongue coatings. Later works such as *Shanghan Shejian* (Observations on Tongue in Cold Damage) and *Maili Zhengyi* (Correct Meaning of Pulse Principles) were all developed based on these foundations. Among them, Du Qingbi's *Yanzheng Shefa* (Verification Methods for Tongue Diagnosis) is particularly concise. This is because the tongue is the orifice of the Heart; diseases of the Zang-Fu organs must manifest on the tongue. Eye diseases originate from the Zang-Fu organs, so it is appropriate to differentiate them by combining tongue coating analysis. This method applies mainly to external contraction diseases, while internal injury diseases rarely present with such signs.
Generally, at the onset of symptoms, if the tongue coating is white, thin, and pale, it indicates that cold pathogen has just entered the Taiyang channel. If white flakes cover the entire tongue, the pathogen is about to transmit to the Yangming channel. A white coating that is dry and thick indicates a heat disease of the Taiyang channel. A white coating that is slippery indicates a concurrent disease of Taiyang and Yangming. A white coating with slight yellow in the center indicates that the pathogen of Taiyang is gradually entering Yangming. If the exterior syndrome is not resolved, use a dual-release method; if the exterior is resolved, use purgation. If diarrhea occurs, use clearing and draining methods. A white coating with slight prickles at the tip indicates a concurrent disease of Shaoyang and Yangming. A white coating with black spots in the center also indicates Shaoyang and Yangming involvement. If the exterior is not resolved, use harmonization; if resolved, use mild purgation. A white coating fully covered with black prickles indicates a combined disease of the three Yang channels. White coating on the left indicates deficiency-heat in Yangming; white coating on the right indicates pathogen affecting Shaoyang. A white coating that is greasy and slippery indicates phlegm.
A tongue without white coating, accompanied by external symptoms of cold limbs, indicates cold directly invading the Shaoyin channel. If the white coating is on the left or right, while the rest shows yellow and black, accompanied by external symptoms of dysentery and pain radiating to the lower abdomen, this is Zang-Jie (organ knotting). For severe heat, use purgation; for no heat, use warming. White coating with a red tip indicates Shaoyang pathology. Tongue coating white at the root and red at the tip indicates concurrent disease of Taiyang and Shaoyang. A white tongue without coating, clear and pale, with external fever, indicates Stomach Qi deficiency. Any change in tongue color without coating belongs to deficiency. A white coating thick like accumulated powder indicates plague pathogen initially attacking the Membrane Source (Mo Yuan). A white coating turning black at both tip and root indicates excessive Metal and Water, with Fire and Earth Qi exhausted internally; although no ominous signs appear externally, death is inevitable. Two black lines in a white coating indicate pathogen from Taiyang and Shaoyang entering the Stomach due to exhaustion of Earth Qi, causing chest binding and pain. Two gray lines in a white coating indicate tongue changes from consuming cold food.
A slightly yellow coating indicates pathogen entering Yangming, representing interior heat syndrome. Deep yellow appearing subsequently indicates increasing heat. Dry or scorched yellow appearing later indicates extreme heat, requiring purgation. Yellow coating at the root and white at the tip indicates more interior than exterior syndrome. Slippery yellow coating indicates Damp-Heat in Yangming. Yellow coating with partitions on top indicates deep pathogenic toxin, requiring urgent purgation. Double-hanging yellow coating indicates Zheng-Yang Yangming syndrome. Yellow coating with macules indicates impending eruption of rashes; if no macules, use specific purgation. Prickles in yellow coating indicate severe Stomach heat. Small black dots in yellow coating indicate pathogen entering the Zang, requiring urgent purgation. Long-standing yellow coating turning black, dry and prickle-covered, indicates extreme excess heat, often untreatable. In such cases, scrape open the coating; if the base under the partition is red, urgent purgation is possible; if black, it is untreatable. Thick, dry black coating in the center indicates heat excess and fluid depletion. Black tongue without coating but dry indicates injured fluids and deficient fire acting. Black tongue with moisture and red edges, presenting with delirium, should be treated with simultaneous attack and tonification for the weak, and urgent purgation for the strong. Summer stroke often presents this tongue; treat with acrid-cool release. In cases of extreme deficiency, combine pulse and symptom analysis. Black center with white slippery edges indicates exterior and interior deficiency-cold.
Pure black coating presents two syndromes: one is extreme fire resembling water, the other is water overcoming fire. Differentiation: fire excess shows thick coating with many prickles; water overcoming fire shows thin coating without prickles. Black tongue with central ulceration is untreatable. Dry, black, short tongue is untreatable. Purple-black tongue postpartum is untreatable. When seeing black, ask if sour, sweet, or salty foods were consumed, as they can dye the tongue black; such tongues are moist, not dry, and the color wipes off. Gray coating is a milder form of black, treated similarly, with Yin-Yang differentiation. Direct invasion of Yin channels causes immediate gray-black tongue without accumulation; transmitted heat syndromes cause dry gray-black coating. Generally, yellow, white, and black have coating, while red and purple show color without coating. Pure red tongue indicates extreme fire excess and deepening plague. Red center indicates Taiyang syndrome. Red tongue with purple blisters at the tip indicates Heart channel heat-toxin. Red tongue with purple macules in the center indicates impending rash eruption. Pale red tongue with red-red points in the center indicates impending jaundice. Red tongue cracking like the character 'Ren' indicates heat transmitting from Yangming to Shaoyin Heart. Pale red tongue cracking like the character 'Chuan' indicates accumulated heat in the Heart channel. Red tongue with prickles indicates heat accumulation in the Stomach. Red tongue with several black lines indicates Yin-Toxin binding in the Liver channel; since Liver governs sinews, tendril-like filaments appear on the tongue. Red tongue with double tongue indicates heat-toxin entering Pericardium; red tongue swollen filling the mouth indicates heat-toxin entering Shaoyang and Yangming; both require pricking to release bad blood. Red tongue bleeding like epistaxis indicates heat injuring Pericardium, requiring cooling blood and stopping bleeding. Red tongue stiff with loss of voice is a death sign; if phlegm, use guiding method; if interior excess, use purgation; survival is occasional. Red tongue rotting like insect erosion indicates Shaoyin plague-toxin, treat with purgation. Red tongue protruding and rolling indicates heat in Heart and Spleen. Trembling red tongue difficult to speak, or flaccid red tongue unable to speak, both indicate extreme Heart-Spleen deficiency, often salvageable with Ginseng. Red tongue dry and shriveled is death, untreatable. Pure purple tongue indicates alcohol toxin. Purple tongue with white center indicates alcohol toxin in Shaoyang. Purple tongue with red center indicates alcohol toxin in Yangming. Pale red tongue with several purple-black tendons in the center indicates Jueyin true cold syndrome. Based on this discussion, one can differentiate deficiency and excess, and distinguish life from death.