（出叶天士《温热论》）
若三焦不从外解，必致里结，里结于何，阳明胃大肠也。凡人之体，脘在腹上，其位居中。或按之痛，
或自痛，或痞胀，当用苦泄，以其入腹近也。必验之于舌。
舌苔或黄或浊，可与小陷胸汤或泻心汤，随证治之。或白不燥，或黄白相兼，或灰白不渴，慎不可遽
投苦泄。其中有外邪未解，里先结者，或邪菀未伸，或素属中冷者，虽有脘中痞闷，宜从开泄，宣通气滞，
以达归于肺，如近俗杏、蔻、橘、桔等，是轻苦微辛，具流动之品可耳。
再前云或黄或浊，须要有地之黄。若光滑者，乃无形湿热，中有虚象，大忌前法。其脐以上为大腹，
或满，或胀，或痛，此必邪已入里矣。表证必无，或十之存一，亦要验于舌。或黄甚，或如沉香色，或老
黄色，或中有断纹，皆当下之，如小承气汤加槟榔、青皮、枳实、元明粉、生首乌等。若未
现此等舌，不宜用此等法。恐其中有湿聚太阴为满，或寒湿
错杂为痛，或气壅为胀，又当以别法治之。
再黄苔不甚浓而滑者，热未伤津，犹可清热透表；若虽薄而干者，邪虽去而津受伤也，苦重之药当禁，
宜甘寒轻剂可也。
再论其热传营，舌色必绛。绛，深红色。初传，绛色中兼黄白色，此气分之邪未尽也，泄卫透营，两和可
也。纯绛鲜泽者，包络受病也，宜犀角、鲜生地、连翘、郁金、石菖蒲等。延之数日，或平素心虚有痰，外
热一陷，里络就闭，非菖蒲、郁金所能开，须用牛黄丸、至宝丹之类，以开其闭，恐其昏厥为痉也。
再色绛而舌中心干者，乃心胃火燔，劫烁津液，即黄连、石膏亦可加入。若烦渴烦热，舌心干，四边
色红，中心或黄或白者，此非血分也，乃上焦气热烁津，急用凉膈散散其无形之热，再看其后转变可也，
慎勿用血药，以滋腻难散。至舌绛，望之若干，手扪之原有津液，此津亏，湿热熏蒸，将成浊痰，蒙闭心包也。
再有热传营血，其人素有瘀伤宿血在胸膈中，挟热而抟，其舌色必紫而暗，扪之湿，当加入散血之品，
如琥珀、丹参、桃仁、丹皮等。不尔，瘀血与热为伍，阻遏正气，遂变如狂、发狂之证。若紫而肿大者，乃
酒毒冲心。若紫而干晦者，肾肝色泛也，难治。
舌色绛而上有粘腻似苔非苔者，中挟秽浊之气，芳香逐之。舌绛欲伸退场门，而抵齿难骤伸者，痰阻舌根，
有内风也。舌绛而光亮，胃阴亡也，急用甘凉濡润之品。若舌绛而干燥者，火邪劫营，凉血清火为要。舌
绛而有碎点白黄者，当生疳也；大红点者，热毒乘心也，用黄连、金汁。其有虽绛
而不鲜，干枯而痿者，肾阴涸也，急以阿胶、鸡子黄、地黄、天冬等救之，缓则恐涸极而无救也。
其有舌独中心绛干者，此胃热、心营受灼也。当于清胃方中，加入清心之品，
否则延及于尖，为津干火盛也，舌尖绛独干，此心火上炎，用导赤散泻其腑。
再舌苔白浓而干燥者，此胃燥气伤也，滋润药中加甘草，含甘守津还之意。舌白而薄者，外感风寒也，当
疏散之。若白干薄者，肺津伤也，加麦冬、花露、芦根汁等轻清之品，为上者上之也。若白苔绛底者，湿遏
热伏也，当先泄湿透热，防其就干也。勿忧之，再从里透于外，则变润矣。初
病舌就干，神不昏者，急加养正透邪之药；若神已昏，此内匮矣，不可救药。
又不拘何色，舌上生芒刺者，皆是上焦热极也，当用青布拭冷薄荷水揩之，即去者轻，旋即生者险矣。
舌苔不燥，自觉闷极者，属脾湿盛也。或有伤痕血迹者，必问曾经搔挖否，不可以有血而便为枯证，仍
从湿治可也。再有神情清爽，舌胀大不能退场门者，此脾湿胃热，郁极化风，而毒延口也，用大黄磨入当用
剂内，则舌胀自消矣。
再舌上白苔粘腻，吐出浊浓涎沫，口必甜味也，为脾瘅病。乃湿热气聚，与谷气相搏，土有余也，盈满
则上泛，当用省头草芳香辛散以逐之则退。若舌上苔如碱者，胃中宿滞
挟浊秽郁伏，当急急开泄，否则闭结中焦，不能从膜原达出矣。
若舌无苔，而有如烟煤隐隐者，不渴肢寒，知挟阴病。如口渴烦热，平时胃燥舌也，不可攻之。若
燥者，甘寒益胃；
若润者，甘温扶中。此何故，外露而里无也。
若舌黑而滑者，水来克火，为阴证，当温之。若见短缩，此肾气竭也，为难治。欲救之，加人参、五味
子，勉希万一。舌黑而干者，津枯火炽，急急泻南补北。若燥而中心浓 者，土燥水竭，急以咸苦下之。
舌淡红无苔者，或干而色不荣者，当是胃津伤，而气无化液也。当用炙甘草汤，不可用寒凉药。
若舌白如粉而滑，四边色紫绛者，温疫病初入膜原，未归胃腑，急急透解，莫待传陷而入，为险恶之病，
且见此舌者，病必见凶，须要小心。
(From Ye Tianshi's *Wenre Lun* [Treatise on Warm Diseases])
If the pathogenic factors of the Sanjiao (Triple Burner) cannot be resolved from the exterior, they will inevitably lead to internal constraint. Where does this internal constraint occur? It occurs in the Yangming Stomach and Large Intestine. In the human body, the epigastrium is located above the abdomen, in a central position. If it is painful upon pressure, or spontaneously painful, or feels stuffy and distended, bitter-draining methods should be employed because the pathology is close to the abdominal cavity. This must be verified by examining the tongue coating.
If the tongue coating is yellow or turbid, Xiao Xianxiong Tang (Small Chest-Harmonizing Decoction) or Xiexin Tang (Drain the Epigastrium Decoction) may be used, treating according to the specific syndrome. If the coating is white but not dry, or a mixture of yellow and white, or grayish-white without thirst, one must be cautious and not hastily administer bitter-draining methods. In these cases, there may be unresolved exterior pathogens with prior internal constraint, or depressed pathogens failing to extend, or constitutions belonging to middle-jiao cold. Although there is stuffiness and oppression in the epigastrium, opening and draining methods are appropriate to circulate Qi stagnation and guide it back to the Lung. For example, commonly used herbs such as Xingren (Apricot Seed), Doukou (Black Cardamom), Chenpi (Tangerine Peel), and Jiegeng (Platycodon Root) are light, slightly bitter, slightly acrid, and possess mobile properties, which suffice.
Regarding the previously mentioned "yellow or turbid," it must refer to a grounded yellow coating (thick and substantial). If the tongue surface is smooth, it indicates formless damp-heat accompanied by deficiency signs; the aforementioned bitter-draining method is strictly contraindicated. The area above the navel is called the greater abdomen. If there is fullness, distension, or pain, the pathogen has definitely entered the interior. Exterior syndromes are certainly absent, or perhaps present in only one out of ten cases; tongue examination is still required. If the coating is deeply yellow, like sedge color, old yellow, or has cracks in the center, purgative methods should be used, such as Xiaochengqi Tang (Minor Order the Qi Decoction) added with Binglang (Areca Seed), Qingpi (Aurantium Peel), Zhishi (Immature Bitter Orange), Yuanmingfen (Mirabilite), and Sheng Shouwu (Raw Polygonum Multiflorum). If these tongue signs do not appear, these methods should not be used. One must consider that the fullness might be due to Dampness gathering in the Taiyin Spleen, pain due to mixed Cold-Dampness, or distension due to Qi congestion; in such cases, other methods should be applied.
Furthermore, if the yellow coating is not very thick but slippery, the heat has not yet damaged the Body Fluids, and clearing heat and venting the exterior is still possible. If the coating is thin but dry, although the pathogen has left, the Body Fluids have been injured; heavy bitter drugs should be prohibited, and light sweet-cold agents are appropriate.
Regarding heat transmitting to the Ying (Nutrient) level, the tongue color must become crimson (deep red). In the initial transmission, if the crimson color is mixed with yellow and white, it indicates that pathogens in the Qi level are not yet exhausted; venting the Wei (Defensive) and penetrating the Ying to harmonize both is sufficient. If the tongue is purely crimson and bright/moist, the Pericardium is affected; herbs such as Xijiao (Rhinoceros Horn - *Note: Substitute with Water Buffalo Horn in modern practice*), Xian Shengdi (Fresh Rehmannia), Lianqiao (Forsythia), Yujin (Curcuma), and Shichangpu (Acorus) are suitable. If delayed for several days, or if the person has chronic Heart deficiency with Phlegm, once external heat sinks in, the interior collaterals become closed; Shichangpu and Yujin alone cannot open it. Niuhuang Wan (Calculus Bovis Pill) or Zhibao Dan (Precious Treasure Pill) must be used to open the closure, lest coma transform into convulsions.
If the tongue is crimson with a dry center, it indicates blazing Fire in the Heart and Stomach consuming Body Fluids; even Huanglian (Coptis) and Shigao (Gypsum) can be added. If there is irritability, thirst, and fever, with a dry tongue center, red sides, and a yellow or white center, this is not a Blood-level issue but Heat in the Upper Jiao scorcing fluids. Liangge San (Cool the Diaphragm Powder) should be urgently used to dissipate formless Heat. Observe subsequent changes. Do not use Blood-invigorating herbs, as their cloying nature makes them difficult to disperse. If the tongue appears dry to the eye but retains moisture when touched, this indicates Body Fluid deficiency with Damp-Heat steaming, potentially forming turbid Phlegm that clouds the Pericardium.
If heat transmits to the Ying and Blood levels, and the person has a history of traumatic blood stasis in the chest/diaphragm, which combines with heat, the tongue color will be purple and dark, moist to the touch. Blood-dispersing herbs such as Hupo (Amber), Danshen (Salvia), Taoren (Peach Kernel), and Danpi (Moutan Bark) should be added. Otherwise, blood stasis and heat combine, obstructing healthy Qi, leading to manic or frenzied states. If the tongue is purple and swollen, it indicates Wine-Toxin rushing to the Heart. If purple and dry/dull, it reflects Kidney and Liver colors emerging, which is difficult to treat.
If the crimson tongue has a sticky, coating-like substance that is not a true coating, it indicates turbid foul qi in the middle; aromatic herbs should be used to expel it. If the crimson tongue wants to extend but cannot exit the mouth, hitting the teeth and unable to extend rapidly, it indicates Phlegm blocking the tongue root and internal Wind. A crimson and bright/shiny tongue indicates loss of Stomach Yin; urgent use of sweet-cool moistening agents is required. A crimson and dry tongue indicates Fire injuring the Ying; cooling the Blood and clearing Fire is essential. Crimson tongue with small white/yellow spots indicates impending aphthous ulcers; large red spots indicate Heat-Toxin attacking the Heart, treated with Huanglian (Coptis) and Jinzhi (Gold Juice). If the tongue is crimson but not bright, dry, and flaccid, it indicates exhaustion of Kidney Yin; Ejiao (Donkey-Hide Gel), Jizihuang (Egg Yolk), Dihuang (Rehmannia), and Tiandong (Asparagus Root) should be used urgently to rescue it; delay risks irreversible exhaustion.
If only the center of the tongue is crimson and dry, it indicates Stomach Heat and scorching of the Heart Ying. Clearing Heart herbs should be added to Stomach-clearing formulas. Otherwise, it spreads to the tip, causing dry fluids and excess Fire. If only the tip is crimson and dry, it indicates Heart Fire flaming upward; Daochi San (Guide Out Redness Powder) should be used to drain the Bladder (Heart's paired organ).
If the white coating is thick and dry, it indicates Stomach Dryness and Qi injury. Add Gancao (Licorice) to moistening herbs, embodying the principle of preserving sweetness to return fluids. Thin white coating indicates External Contraction of Wind-Cold; dispersing is indicated. Dry thin white coating indicates Lung Jin (Fluids) injury; add Maidong (Ophiopogon), Hualu (Flower Dew), and Lugenzhi (Reed Root Juice), light and clear herbs, following the principle of "treating upper disorders with upper-acting agents." White coating with a crimson base indicates Dampness suppressing Heat; first resolve Dampness and vent Heat to prevent drying. Do not worry; venting from interior to exterior will restore moisture. If the tongue is dry at onset but consciousness is clear, urgently add herbs that nourish Righteous Qi and expel pathogens. If consciousness is lost, it indicates internal depletion and is incurable.
Regardless of color, prickles on the tongue indicate extreme Heat in the Upper Jiao. Wipe with green cloth dipped in cold mint water. If pricles disappear easily, the condition is mild; if they reappear immediately, it is dangerous.
If the coating is not dry but the patient feels extreme stifling, it belongs to Spleen Dampness Excess. If there are scratch marks/blood, ask if scratched; do not assume dryness due to blood; treat as Dampness. If mental state is clear but the tongue is swollen and cannot retract, it is Spleen Dampness and Stomach Heat,郁极化风 (stagnation transforming into Wind), with toxin spreading to the mouth. Grind Dahuang (Rhubarb) into the prescribed dose to reduce swelling.
If the tongue has a sticky white coating, expelling turbid thick saliva, and the mouth tastes sweet, it is Pi Dan (Spleen Pesty Disease/Damp-Heat accumulation). This is Damp-Heat gathering, combusting with Grain Qi, indicating Earth Excess overflowing upward. Use Shengtoucao (Vetiver Root) to aromatically and acridly disperse it. If the coating resembles alkali/salt crust, it indicates old food retention with turbid foul qi stagnating in the Stomach; urgent opening/draining is needed, otherwise it closes the Middle Jiao and cannot exit via the Membrane Source.
If the tongue has no coating but shows faint smoke-black patches, without thirst and with cold limbs, it indicates concurrent Yin disease. If thirsty with fever, it is a normally dry Stomach tongue; do not purge. If dry, use sweet-cold to benefit Stomach; if moist, use sweet-warm to support Middle. Why? Because the exterior shows false heat while the interior lacks true heat.
If the tongue is black and slippery, Water overcoming Fire indicates a Yin syndrome; warm it. If short/retracted, Kidney Qi is exhausted, making it difficult to treat. To rescue, add Renshen (Ginseng) and Wuweizi (Schisandra) for a slim hope. If black and dry, Body Fluid exhaustion and blazing Fire require urgently draining South (Heart/Fire) and tonifying North (Kidney/Water). If dry and thick in the center, Earth Dryness and Water Exhaustion require urgent salty-bitter purgation.
Pale red tongue without coating, or dry and lacking luster, indicates Stomach Jin injury and Qi failing to generate fluids. Use Zhigancao Tang (Honey-Fried Licorice Decoction); do not use cold/cool herbs.
If the tongue is white like powder and slippery, with purple/crimson edges, it indicates Warm Epidemic Pathogen entering the Membrane Source, not yet in the Stomach Fu. Urgently vent and resolve; do not wait for transmission into the interior, which becomes perilous. Seeing this tongue indicates severe prognosis; exercise caution.