口者。脾之所主。胃与大肠脉之所挟。经云。脾气通于口。脾和则口能知五味矣。此脾之主
于口也。又云。胃足阳明之脉。挟口。下交承浆。又云。大肠手阳明之脉。挟口交人中。此胃与
大肠之脉挟于口也。脾热则口甘。肝热则口酸。心热则口苦。肺热则口辛。肾热则口咸。胃热则
口淡。口甘。经云。有病口甘者。此五脏之溢也。名曰脾瘅。治之以兰。除
陈气也。兰香饮子。若脉弦滑。兼嘈杂。属痰火。滚痰丸。此指实火而言。平人口甘欲渴。或小
便亦甜而浊。俱属土中湿热。脾津上乘。久之必发痈疽。须断浓味气恼。服三黄汤加兰叶、白芍、
生地。燥渴甚者。为肾虚。日服加减八味丸。可保无虞。中消。脾液上乘口甘者。兰香饮子。老
人虚人。脾胃虚热不能收敛津液而口甘者。当滋补脾气。补中益气去升、柴。加兰香、煨葛根。
口苦。经云。有病口苦。名曰胆瘅。夫胆者中精之府。五脏取决于胆。咽为之使。此人数谋虑不
决。故胆虚气上溢而口为之苦也。龙胆泻肝汤。或小柴胡加麦冬、枣仁。不应。本方加川连、胆
草。口酸。肝胆实热也。佐金丸加神曲、草龙胆。口辛。肺气上溢也。生脉散加桑皮、地骨皮、
黄芩。口咸。肾液上乘也。六味地黄丸加五味、乌 骨。口淡为胃热。而有虚实。实则甘露饮加
广藿香。病后胃虚口淡。六君子加黄 、当归。口涩。肝邪逆于肺。气虚火旺也。黄芩、葛根、
防风、薄荷、栝蒌、茯苓。口疮。经云。膀胱遗热于小肠。膈肠不便。上为口糜。盖小肠者。心
之府也。此举邪热之一端耳。心属君火。主五脏六腑之火。故诸经之热。皆应于心。心脉布舌上。
脾脉布舌下。二经之火为病。皆当用寒凉施治。但有涎者。兼取其涎。若元藏虚冷。上攻头热。
足冷口疮。用附子理中汤、连理汤。并用当归、附子蜜煎含咽。有用生附子末涂脚心者。若此之
类。皆是治龙火之法。阴邪上迫。心肺之阳不得下降。故用温热主治。或散于上。或散于下。随
其攸利。胃中有热。脉洪大而实者。服凉膈散、金花丸。并用黄柏一味蜜炙含之。忌犯酒醋。犯
之难愈。又好饮酒人。多有此证。易老用五苓散、导赤散。相和治之。服凉药不愈者。此酒色过
度。劳役不睡。舌上光滑而无皮。或因忧思损伤中气。虚火泛上无制。必用理中汤。甚者加附子。
并用蜜煎附子噙之。口疮以甘草半寸。白矾钱许。含化咽津。口疮久不愈。以五倍子末掺之。或
煎汤漱。或煎汤泡白矾漱。盖酸能收敛也。口疮甚
者。含焰硝、硼砂。勿开口。并用南星末。醋调贴足心涌泉穴以引热下行。又方。五倍子一两。
蜜炙黄柏、滑石各半两。铜绿三钱。麝香少许。为末掺之。舌疮口破疼痛。以巴豆半枚。生研。
和米饮一豆大。杵和。贴印堂对额间。约半刻许。觉红就去。不可泡起。小儿减半。随即痊愈。
戴复庵云。下虚上盛。致口舌生疮。宜用镇坠之药。以苏子降气汤。或盐汤下养正丹。口臭。年
高水弱。奉养太过。浓味。及服食补阳药。口糜臭不可近。甘露饮加犀角、茵陈。及浓煎香薷汁
含之。徐徐咽下。口中如胶而臭。知母、地骨皮、桑皮、山栀、麦冬、甘草、食盐。煎汤噙下。
壮盛之人。凉膈散甚佳。痰壅气浊而臭。宜盐汤探吐之。
子和治一男子。二十余岁。病口中气出。臭如登厕。夫肺金本主腥。金为火所乘。火主臭。
应使如是也。久则成腐。腐者肾也。此亢极反兼水化也。病在上。宜涌之。以瓜蒂散涌而去其七
分。夜以神 丸、浚川散下五七行。比旦而臭断。但药性犷悍。不宜轻用。
口，是脾脏所主管的部位。足阳明胃经和手阳明大肠经的脉气都挟持着口部。医经上说：“脾气通于口”，脾的功能调和，口就能辨别五味。这是脾对口的支配作用。又说：“足阳明胃经，挟行于口旁，向下交会于承浆穴”；又说：“手阳明大肠经，挟行于口旁，交会在人中穴”。这是胃和大肠的经脉挟持于口部的表现。
脾有热则口中发甜。肝有热则口中发酸。心有热则口中发苦。肺有热则口中发辛（辣味）。肾有热则口中发咸。胃有热则口中发淡。
关于口中发甜：医经说，有病人口中发甜的，这是五脏精气外溢的表现，称为“脾瘅”（脾热导致的口甘病）。治疗用兰草（佩兰），以清除陈久的湿热之气。可用兰香饮子。如果脉象弦滑，兼有嘈杂感，属于痰火证，用滚痰丸。这里指的是实火而言。普通人若口甘且想喝水，或者小便也甜而浑浊，都属于脾胃湿热，脾津上泛。时间久了必然发生痈疽。必须断绝肥甘厚味和气恼情绪，服用三黄汤加兰叶、白芍、生地。燥渴严重的，属于肾虚，每日服用加减八味丸，可以保全无虞。如果是中消证，因脾液上乘导致口甘的，用兰香饮子。老年人或体虚之人，因脾胃虚热不能收敛津液而导致口甘的，应当滋补脾气，用补中益气汤去掉升麻、柴胡，加兰香、煨葛根。
关于口中发苦：医经说，有病人口中发苦的，称为“胆瘅”。胆是中精之府，五脏六腑取决于胆，咽喉是胆气通行的通道。这是因为人谋虑不决，导致胆虚气上溢而口苦。可用龙胆泻肝汤，或小柴胡汤加麦冬、枣仁。若无效，在原方基础上加黄连、龙胆草。
关于口中发辛：这是肺气上溢。用生脉散加桑白皮、地骨皮、黄芩。
关于口中发咸：这是肾液上乘。用六味地黄丸加五味子、乌骨（乌贼骨）。
口中发淡是胃热所致，但有虚实之分。实证用甘露饮加广藿香。病后胃虚导致口淡的，用六君子汤加黄芪、当归。
口中发涩：这是肝邪逆犯于肺，气虚火旺。药用黄芩、葛根、防风、薄荷、瓜蒌、茯苓。
口疮：医经说，膀胱遗热于小肠，导致膈肠不便，热气上蒸成为口糜（口腔黏膜溃烂）。小肠是心的腑。这只是举出邪热的一种情况罢了。心属君火，主宰五脏六腑之火，所以各经的热邪都会应于心。心经脉络布于舌上，脾经脉络布于舌下。这两经火热致病，都应当用寒凉药物治疗。但如果伴有涎沫多者，需兼顾化痰涎。若是元阳亏虚寒冷，寒气上攻头部发热、脚冷并伴口疮的，用附子理中汤、连理汤。并用当归、附子蜜煎含咽。也有用生附子末涂脚心的。这类方法，都是治疗“龙火”（相火妄动）的方法。阴邪上迫，心肺之阳不得下降，所以用温热药主治。或发散于上，或发散于下，随其便利而定。
胃中有热，脉洪大而实的，服凉膈散、金花丸。并用黄柏一味蜜炙含之。忌食酒醋，犯了就难愈。喜欢喝酒的人，多有此证。李东垣用五苓散、导赤散，混合治疗。服用凉药不愈的，这是酒色过度，劳役失眠，舌上光滑无苔。或因忧思损伤中气，虚火泛上无制。必须用理中汤。严重的加附子。并用蜜煎附子噙化。
口疮用甘草半寸，白矾少许，含化咽津。口疮久不愈的，用五倍子末撒敷。或煎汤漱口。或煎汤泡白矾漱口。因为酸味能收敛。口疮严重的，含焰硝、硼砂，不要开口。并用南星末，醋调贴足心涌泉穴以引热下行。又一方：五倍子一两，蜜炙黄柏、滑石各半两，铜绿三钱，麝香少许，研为末撒敷。
舌疮口破疼痛，用巴豆半枚，生研，和米饮如豆大，捣匀，贴印堂（两眉之间额间）。约半刻许，感觉发红就去掉，不可起泡。小儿减半，随即痊愈。
戴复庵说：下虚上盛，导致口舌生疮，宜用镇坠之药，用苏子降气汤，或用盐汤送服养正丹。
口臭：年高肾水弱，奉养太过，吃浓味食物，及服用补阳药，导致口糜臭不可近。用甘露饮加犀角、茵陈，以及浓煎香薷汁含漱，徐徐咽下。口中如胶而臭的，用知母、地骨皮、桑白皮、山栀、麦冬、甘草、食盐，煎汤噙下。壮盛之人，用凉膈散甚佳。痰壅气浊而臭的，宜用盐汤探吐。
张子和治一男子，二十多岁，病人口中出气，臭如登厕。肺金本主腥，金被火乘，火主臭，所以气味如此。久了就会成腐，腐属于肾，这是亢极反兼水化的表现。病在上焦，宜用涌吐法。用瓜蒂散涌吐去其七分邪气，晚上用神保丸、浚川散攻下五六次。到第二天早上臭味就断了。但药性猛烈，不宜轻用。
The mouth is the area governed by the Spleen. The meridians of the Stomach and Large Intestine flank the mouth. The Classics state: "Spleen Qi connects with the mouth." When the Spleen functions harmoniously, the mouth can perceive the five flavors. This describes the Spleen's dominion over the mouth. It is also stated: "The Foot-Yangming Stomach Meridian flanks the mouth and descends to intersect at Chengjiang (CV24)." And again: "The Hand-Yangming Large Intestine Meridian flanks the mouth and intersects at Renzhong (GV26)." This describes how the meridians of the Stomach and Large Intestine flank the mouth.
If the Spleen has heat, the mouth tastes sweet. If the Liver has heat, the mouth tastes sour. If the Heart has heat, the mouth tastes bitter. If the Lung has heat, the mouth tastes pungent. If the Kidney has heat, the mouth tastes salty. If the Stomach has heat, the mouth tastes bland.
Regarding a sweet taste in the mouth: The Classics state that those with a sweet taste in the mouth are suffering from an overflow of the essence of the five Zang organs, a condition named Pi Dan (Spleen Heat leading to sweet taste). Treatment involves using Lan Cao (Pei Lan, *Eupatorii Herba*) to eliminate stale damp-heat. Lan Xiang Yin Zi (Orchid Fragrance Decoction) may be used. If the pulse is wiry and slippery, accompanied by a sensation of hunger discomfort (zao), it belongs to Phlegm-Fire; Gun Tan Wan (Rolling Phlegm Pill) is indicated. This refers specifically to Excess Fire. In ordinary people, if there is a sweet taste with thirst, or if urine is also sweet and turbid, it all belongs to Damp-Heat in the Earth element (Spleen/Stomach), where Spleen fluids ascend. Over time, this will inevitably develop into carbuncles and sores. One must abstain from rich foods and emotional anger, and take San Huang Tang (Three Yellow Decoction) added with Lan Ye (Orchid Leaf), Bai Shao (White Peony Root), and Sheng Di (Rehmannia Root). For severe dryness and thirst, it indicates Kidney Deficiency; taking Jia Jian Ba Wei Wan (Modified Eight-Ingredient Pill) daily can ensure safety. For Zhong Xiao (Middle Wasting-Thirst), where Spleen fluids ascend causing a sweet taste, Lan Xiang Yin Zi is used. For elderly or deficient individuals, where Spleen-Stomach Deficient-Heat fails to consolidate fluids causing a sweet taste, one should tonify Spleen Qi using Bu Zhong Yi Qi Tang (Tonify the Middle and Augment the Qi Decoction), removing Sheng Ma (Cimicifuga Rhizome) and Chai Hu (Bupleurum Root), and adding Lan Xiang (Orchid Fragrance) and Wei Ge Gen (Calcined Kudzu Root).
Regarding a bitter taste in the mouth: The Classics state that those with a bitter taste in the mouth are suffering from Dan Dan (Gallbladder Heat). The Gallbladder is the residence of pure essence, and the five Zang organs depend on it; the throat serves as its conduit. This occurs because people hesitate in their deliberations, leading to Gallbladder Deficiency and Qi overflowing upward, causing bitterness. Long Dan Xie Gan Tang (Gentian Decoction to Drain the Liver) may be used, or Xiao Chai Hu Tang (Minor Bupleurum Decoction) added with Mai Dong (Ophiopogon Tuber) and Zao Ren (Ziziphus Seed). If ineffective, add Huang Lian (Coptis Rhizome) and Dan Cao (Gentiana Root) to the base formula.
Regarding a sour taste in the mouth: This is Excess Heat of the Liver and Gallbladder. Zuo Jin Wan (Assist Metal Pill) added with Shen Qu (Medicated Leaven) and Cao Long Dan (Gentiana Root) is indicated.
Regarding a pungent taste in the mouth: This is Lung Qi overflowing upward. Sheng Mai San (Generate the Pulse Powder) added with Sang Bai Pi (Mulberry Root Bark), Di Gu Pi (Lycium Bark), and Huang Qin (Scutellaria Root) is indicated.
Regarding a salty taste in the mouth: This is Kidney fluid ascending. Liu Wei Di Huang Wan (Six-Ingredient Rehmannia Pill) added with Wu Wei Zi (Schisandra Berry) and Wu Gu (Cuttlefish Bone) is indicated.
A bland taste is due to Stomach Heat, which can be either Excess or Deficiency. In Excess cases, Gan Lu Yin (Sweet Dew Decoction) added with Guang Huo Xiang (Patchouli) is used. After illness, if Stomach Deficiency causes a bland taste, Liu Jun Zi Tang (Six-Gentlemen Decoction) added with Huang Qi (Astragalus Root) and Dang Gui (Angelica Sinensis) is used.
A dry/astringent taste in the mouth: This is Liver pathogen counterflowing to the Lung, with Qi Deficiency and Fire Prosperity. Herbs include Huang Qin (Scutellaria Root), Ge Gen (Kudzu Root), Fang Feng (Saposhnikovia Root), Bo He (Mint), Gua Lou (Trichosanthes Fruit), and Fu Ling (Poria).
Mouth ulcers (Kou Chuang): The Classics state that Bladder heat is transmitted to the Small Intestine, causing obstruction in the diaphragm and intestines, rising upward to become Kou Mi (oral mucosal erosion). The Small Intestine is the Fu organ of the Heart. This merely illustrates one aspect of evil heat. The Heart belongs to Ministerial Fire and governs the fire of the five Zang and six Fu organs; thus, heat from all meridians responds to the Heart. The Heart meridian spreads over the tongue, and the Spleen meridian spreads under the tongue. Diseases of fire in these two meridians should be treated with cold/cooling herbs. However, if there is excessive saliva, phlegm-saliva must also be addressed. If Yuan Yang (Primordial Yang) is deficient and cold, with cold attacking upward causing head heat, foot cold, and mouth ulcers, use Fu Zi Li Zhong Tang (Aconite Regulate the Middle Decoction) or Lian Li Tang (Coix and Licorice Decoction). Also, use Dang Gui (Angelica Sinensis) and Fu Zi (Aconite Root) honey-fried for holding in the mouth. Some use raw Fu Zi powder applied to the sole of the foot. Such methods are treatments for "Dragon Fire" (Hyperactive Ministerial Fire). When Yin pathogens press upward, preventing Heart-Lung Yang from descending, warm/hot herbs are used to treat the root. They may disperse upward or downward, according to convenience.
If there is heat in the Stomach and the pulse is surging and large/excess, take Liang Ge San (Cool the Diaphragm Powder) or Jin Hua Wan (Golden Flower Pill). Also, hold a piece of honey-fried Huang Bo (Phellodendron Bark) in the mouth. Avoid alcohol and vinegar; violating this makes healing difficult. People who enjoy drinking often have this syndrome. Li Dongyuan used Wu Ling San (Five-Ingredient Powder with Poria) and Dao Chi San (Direct Outward Red Powder) mixed together for treatment. For those not healed by cooling medicines, this is due to excess alcohol and sexual activity, labor, and sleeplessness, resulting in a smooth tongue without coating. Or it is due to worry and thought damaging Middle Qi, with Deficient Fire floating up uncontrollably. One must use Li Zhong Tang (Regulate the Middle Decoction). Severe cases add Fu Zi. Also, hold honey-fried Fu Zi in the mouth. For mouth ulcers, hold half a cun of Gan Cao (Licorice Root) and a small amount of Bai Fan (Alum), swallowing the saliva. For chronic mouth ulcers, sprinkle Mei Zi Bei (Chinese Gall) powder. Or decoct for rinsing. Or soak Bai Fan in decoction for rinsing, as sour flavors can astringe. For severe mouth ulcers, hold Yan Xiao (Saltpeter) and Peng Sha (Borax), keeping the mouth closed. Also, apply Nan Xing (Arisaema Rhizome) powder mixed with vinegar to the Yongquan (KI1) acupoint on the sole to guide heat downward. Another prescription: Mei Zi Bei (Chinese Gall) 1 liang, honey-fried Huang Bo (Phellodendron Bark) and Hua Shi (Talcum) each 0.5 liang, Tong Lv (Verdigris) 3 qian, and a little She Xiang (Musk), ground into powder and sprinkled.
For tongue ulcers and broken mouth pain, use half a Ban Dou (Croton Seed), raw and ground, mixed with rice water to the size of a bean, pounded and applied to the Yin Tang (point between eyebrows) on the forehead. Remove after about half a ke when redness appears; do not allow blistering. Reduce dose for children; recovery follows immediately.
Dai Fuan said: Lower Deficiency and Upper Excess causing mouth and tongue ulcers should be treated with sedating/heavy-settling herbs, such as Su Zi Jiang Qi Tang (Perilla Seed Descending Qi Decoction), or Yang Zheng Dan (Nourish Righteousness Pill) taken with salt water.
Bad breath (Kou Chou): In the elderly with weak Kidney Water, excessive nourishment, rich foods, and consumption of Yang-tonifying drugs, Kou Mi (oral erosion) becomes foul-smelling. Use Gan Lu Yin (Sweet Dew Decoction) added with Xi Jiao (Rhinoceros Horn - *note: substitute with Buffalo Horn in modern practice*), Yin Chen (Artemisia Capillaris), and strong decoction of Xiang Ru (Mosla) for holding in the mouth, swallowing slowly. If the mouth feels sticky and foul, use Zhi Mu (Anemarrhena Rhizome), Di Gu Pi (Lycium Bark), Sang Bai Pi (Mulberry Root Bark), Shan Zhi (Gardenia Fruit), Mai Dong (Ophiopogon Tuber), Gan Cao (Licorice Root), and Shi Yan (Salt), decocted for holding in the mouth. For robust individuals, Liang Ge San (Cool the Diaphragm Powder) is excellent. For turbid phlegm and Qi causing foul odor, induce vomiting with salt water.
Hezi treated a man in his twenties whose breath smelled like a latrine. Metal (Lung) naturally smells fishy; when Metal is overcome by Fire, Fire causes foul odors, hence such smell. Over time, it becomes putrid; putrefaction belongs to Water (Kidney). This is extreme hyperactivity mimicking Water transformation. Since the disease is in the upper jiao, emesis is appropriate. Use Gua Di San (Melon Sepal Powder) to vomit out seven-tenths of the pathogen. At night, use Shen Bao Wan and Jun Chuan San to purge five or six times. By morning, the odor ceased. However, the drug properties are harsh and should not be used lightly.