五脏六腑。皆秉气于胃。五脏六腑之气。亦皆发见于胃。口者。胃之门户。故五脏六腑之气。皆见于此。口苦
是胆热。小柴胡汤。加黄连治之。口甘是脾热。甲己化土汤。加天花粉茵陈蒿炒栀子茯苓枳壳浓朴黄芩
石膏治之。口酸是湿热。观炎天羹肉过夜则酸。便知酸是湿热所化。葛根黄连黄芩汤。加防己茵陈木通
滑石花粉云苓治之。或苍术黄柏黄连吴茱萸亦治之。口咸是脾湿。润下作咸。脾不化水。故咸也。二陈汤。
加旋复花藿香白芍檀香吴茱萸治之。胃苓汤亦治之。或六味地黄汤。加旋复花牛膝白前根。从肾中化
水。纳之下行。以隔治之。口淡是胃虚。六君子汤。随寒热加减治之。口涩是风热。通圣散。去芒硝大黄治之。
口麻是血虚。圣愈汤。加薄荷治之。口臭是食积之火。平胃散。加山楂神曲麦芽黄芩石膏治之。口中糜烂。
是膀胱遗热于小肠。热气不得下泄。故糜及于口。导赤散。加天花粉天门冬麦门冬金银花灯心车前子
栀子治之。喉腥是肺火痰滞。泻白散。合甘桔汤。再加射干马兜铃黄芩杏仁川贝母天冬麦冬百合栝蒌
霜治之。总而论之。口乃胃之门户。总以治胃为主。宜分舌热。用甘露饮平胃散。加减治之。
舌为心之苗。而居口中。脏腑之气。发见于口者。多着于舌。故即舌苔。可以诊知脏腑诸病。伤寒邪在表者。
舌无苔。在半表半里者。舌乃有苔。入里则苔结矣。故凡有苔。皆系内证。苔白为湿热。小柴胡汤。加花粉石
膏滑石木通治之。苔黄为燥热。犀角地黄汤。加知母石膏天花粉大黄枳壳治之。黑苔芒刺为实热。大承
气汤治之。若苔黑而舌滑润者。乃水极似火。真寒假热之证。四逆汤。加猪胆汁人尿葱白治之。血家虚火。
又宜地黄汤。加肉桂牛膝五味子龙骨。以引导之。
又凡舌肿舌裂。痛疮等证。均是心脾火毒。泻心汤治之。大清凉散亦治之。若舌根木强。或舌短缩者。皆是
少阴经风邪内动。阴火上腾之候。地黄饮子。加羚羊角治之。
上所论口舌诸证。血家间亦有之。要宜以血证为主。参以上各法。斯为本末兼权之术。
The Zang and Fu organs all derive their Qi from the Stomach. The Qi of the Zang and Fu organs also manifests in the Stomach. The mouth is the gateway of the Stomach; therefore, the Qi of the Zang and Fu organs all manifest here.
Bitter taste in the mouth indicates Gallbladder Heat (Dan Re). It is treated with Xiao Chai Hu Tang (Minor Bupleurum Decoction) plus Huang Lian (Coptidis Rhizoma).
Sweet taste in the mouth indicates Spleen Heat (Pi Re). It is treated with Jia Ji Hua Tu Tang (Jia Ji Transforming Earth Decoction) plus Tian Hua Fen (Trichosanthis Radix), Yin Chen Hao (Artemisiae Scopariae Herba), fried Zhi Zi (Gardeniae Fructus), Fu Ling (Poria), Zhi Ke (Aurantii Fructus), Hou Po (Magnoliae Officinalis Cortex), Huang Qin (Scutellariae Radix), and Shi Gao (Gypsum Fibrosum).
Sour taste in the mouth indicates Damp-Heat (Shi Re). Observing that soup and meat turn sour overnight in summer reveals that sourness is transformed by Damp-Heat. It is treated with Ge Gen Huang Lian Huang Qin Tang (Kudzu, Coptis, and Scutellaria Decoction) plus Fang Ji (Stephaniae Tetrandrae Radix), Yin Chen, Mu Tong (Akebiae Caulis), Hua Shi (Talcum), Hua Fen, and Yun Ling. Alternatively, Cang Zhu (Atractylodis Rhizoma), Huang Bai (Phellodendri Cortex), Huang Lian, and Wu Zhu Yu (Evodiae Fructus) may also be used.
Salty taste in the mouth indicates Spleen Dampness (Pi Shi). "Moisture descending produces salt." Since the Spleen fails to transform water, saltiness appears. It is treated with Er Chen Tang (Two-Cured Decoction) plus Xuan Fu Hua (Inulae Flos), Huo Xiang (Agastaches Herba), Bai Shao (Paeoniae Radix Alba), Tan Xiang (Santalum Album Lignum), and Wu Zhu Yu. Wei Ling Tang (Stomach-Ling Decoction, a combination of Ping Wei San and Wu Ling San) is also effective. Alternatively, Liu Wei Di Huang Tang (Six-Ingredient Rehmannia Decoction) plus Xuan Fu Hua, Niu Xi (Achyranthis Bidentatae Radix), and Bai Qian Gen (Cynanchi Stauntonii Radix) can be used to transform water in the Kidney and guide it downward, employing the "remote treatment" method.
Insipid taste in the mouth indicates Stomach Deficiency (Wei Xu). It is treated with Liu Jun Zi Tang (Six-Gentlemen Decoction), modified according to Cold or Heat.
Astringent taste in the mouth indicates Wind-Heat (Feng Re). It is treated with Feng Wang Tong Sheng San (Wind-Blocking Universal Salvation Powder), removing Mang Xiao (Natrii Sulfas) and Da Huang (Rhei Radix et Rhizoma).
Numbness in the mouth indicates Blood Deficiency (Xue Xu). It is treated with Sheng Yu Tang (Holy Rescue Decoction) plus Bo He (Menthae Haplocalycis Herba).
Bad breath indicates Fire from Food Retention (Shi Ji Zhi Huo). It is treated with Ping Wei San (Peaceful Stomach Powder) plus Shan Zha (Crataegi Fructus), Shen Qu (Massa Medicata Fermentata), Mai Ya (Hordei Fructus Germinatus), Huang Qin, and Shi Gao.
Ulceration in the mouth indicates residual Heat from the Bladder transferring to the Small Intestine. The Heat cannot descend and discharge, thus eroding the mouth. It is treated with Dao Chi San (Guide Out Redness Powder) plus Tian Hua Fen, Tian Dong (Asparagi Radix), Mai Dong (Ophiopogonis Radix), Jin Yin Hua (Lonicerae Japonicae Flos), Deng Xin Cao (Junci Medullia), Che Qian Zi (Plantaginis Semen), and Zhi Zi.
Fishy odor in the throat indicates Lung Fire with Phlegm Stagnation (Fei Huo Tan Zhi). It is treated by combining Xie Bai San (Drain White Powder) with Gan Jie Tang (Licorice and Platycodon Decoction), plus She Ye (Belamcandae Rhizoma), Ma Dou Ling (Aristolochiae Manshuriensis Fructus), Huang Qin, Xing Ren (Pruni Semen), Chuan Bei Mu (Fritillariae Cirrhosae Bulbus), Tian Dong, Mai Dong, Bai He (Lilii Bulbus), and Gua Lou Shuang (Benincasae Exocarpium Pulveratum).
In summary, the mouth is the gateway of the Stomach; treatment primarily focuses on the Stomach. One should differentiate tongue heat, using Gan Lu Yin (Sweet Dew Drink) and Ping Wei San, modified as needed.
The tongue is the sprout of the Heart and resides in the mouth. The Qi of the Zang and Fu organs manifesting in the mouth often attaches to the tongue. Therefore, by observing the tongue coating, one can diagnose various diseases of the Zang and Fu organs. When Sha Yang pathogenic factors are in the Exterior, there is no tongue coating. When they are in the Half-Exterior/Half-Interior, a tongue coating appears. When they enter the Interior, the coating becomes thick and adherent. Thus, any tongue coating indicates an Internal Syndrome.
White coating indicates Damp-Heat, treated with Xiao Chai Hu Tang plus Hua Fen, Shi Gao, Hua Shi, and Mu Tong.
Yellow coating indicates Dry-Heat, treated with Xi Jiao Di Huang Tang (Rhino Horn and Rehmannia Decoction) plus Zhi Mu (Anemarrhenae Rhizoma), Shi Gao, Tian Hua Fen, Da Huang, and Zhi Ke.
Black coating with prickles indicates Excess Heat, treated with Da Cheng Qi Tang (Major Order the Qi Decoction). If the black coating is accompanied by a slippery and moist tongue surface, it indicates Water Extremity resembling Fire, a pattern of True Cold and False Heat. It is treated with Si Ni Tang (Four Counterflow Decoction) plus Zhu Dan Zhi (Porci Bile), Ren Niao (Human Urine), and Cong Bai (Allii Fistulosi Bulbus). For patients with blood disorders suffering from Deficient Fire, Di Huang Tang (Rehmannia Decoction) plus Rou Gui (Cinnamomi Cortex), Niu Xi, Wu Wei Zi (Schisandrae Chinensis Fructus), and Long Gu (Fossilia Ossis Mastodi) should be used to guide the fire back to its source.
Furthermore, conditions such as swollen tongue, cracked tongue, painful sores, etc., are all due to Heart and Spleen Fire-Toxin. They are treated with Xie Xin Tang (Drain the Heart Decoction) or Da Qing Liang San (Great Cooling and Clearing Powder). If the base of the tongue is stiff or the tongue is short and retracted, it indicates internal stirring of Wind Pathogen in the Shao Yin Meridian and rising of Deficient Fire. It is treated with Di Huang Yin Zi (Rehmannia Elixir) plus Ling Yang Jiao (Saigae Tataricae Cornu).
The aforementioned oral and lingual syndromes may also occur in patients with blood disorders. However, treatment should prioritize the blood disorder, referencing the above methods. This constitutes a strategy that addresses both root and branch.