舌为心苗。脾脉连舌本，散舌下。肾脉挟舌本。膀胱、三焦筋并结舌本。肝脉
络舌本。
舌胎，见四诊察舌条。舌衄，详血门。舌肿痛，舌下肿似又生一小舌，名重舌。
肿硬不柔活，名木舌。皆心、脾、胃经蕴热，凉膈散（见发热）、栀子金花汤（见唇）、玄参升
麻汤。热而痰盛者，清热化痰汤。重舌外治，桑皮、僵蚕、发灰，醋调敷舌下，金
丹（见咽喉）吹更妙。并用黄连、犀角、山栀、丹皮、生地、木通、赤芍、麦冬、连翘、
生甘草。木舌肿甚，色如猪肝，满口胀塞，先于舌尖或两旁刺之，又看舌下有如蝼
蛄、卧蚕肿突者刺出紫血，棉蘸甘草水润之，用百草霜细研醋调敷舌上下，或
同盐等分井花水调涂。凡舌肿胀，宜刺舌尖或舌上或两旁出血，惟舌下廉泉穴属肾
经，慎刺，恐出血太过则喑。按木舌有不痛者，痰湿盛于热也。又有麻舌，火嘘痰
沸故麻，或血虚气涩亦麻，理详痹门。舌强，舌肿必强，即木舌之不能柔活也，
牛黄散。又用蛇蜕烧存性，全蝎等分，为细末敷之。又有痰涎滞其筋脉，
不能转运而强者。（详中风门。）又有热极燥血不能荣其筋脉，拘急而强者，（详中风门。）甚则
为卷缩。舌卷缩，肝经热极，血枯不能荣筋，故卷缩。又伤寒直中阴经，寒甚筋脉
收引，亦卷缩。并详伤寒。然《经》谓∶邪客三焦之络，喉痹舌卷，口干心烦。又
谓∶大肠筋病，转筋舌卷。则不止肝之一经为然可知，亦不止伤寒一证为然可知矣。
风寒湿所中而舌强卷缩，小续命汤。（见中风。）挟热，升麻汤加桔梗漱之，碧雪
敷之。舌出不收，热甚，（纵长之与肿大，一也，故皆为热甚。）珠末、冰片等分敷之，内
服黄芩、僵蚕、胆星、乌药、竹沥等，去痰清热。伤寒热毒攻心，及伤寒愈后不能
调摄，（阴阳易常有此。）与中毒、大惊、产后俱有之。甚有出数寸者，用巴豆一枚，去油
取霜，纸捻卷之，内鼻中，舌自收，此治伤寒后不调摄者。产后者，朱砂末
敷舌，令作产子状，以二女掖之，乃于壁外潜累盆盎，触倒作声，声闻而
舌收矣。余者，雄鸡冠血浸舌，或冬青浓汁浸。舌纵流涎，涎从舌下廉泉穴出，乃
肾火盛而逼津液上出也，神龟滋阴丸，（见痿芩）、连、栀、柏、竹沥、姜汁等可用。舌
干裂，花粉散、泻心汤。舌生疮，甘露饮。口舌生疮。体倦食少，清热补血汤。不
应，补中益气汤（见气）加五味子。思虑太过，血伤火动者，归脾汤（见血）加柴胡、栀子、
丹皮。舌下生水泡，初起一，渐至七八枚，名连珠疳，吹口疳药。（见口。）
舌是心的外候。脾经的脉气连接舌根，散布于舌下。肾经的脉气夹行于舌根两侧。膀胱经和三焦经的筋脉都结聚于舌根。肝经的脉气联络舌根。
舌苔的情况，详见“四诊察舌”条目。舌衄（舌体出血），详见“血门”。舌部肿痛，若舌下肿胀似又生出一个小舌头，称为重舌。若舌体肿胀坚硬、不柔软灵活，称为木舌。这些病症多因心、脾、胃三经蕴积热邪所致，可用凉膈散（见发热）、栀子金花汤（见唇）、玄参升麻汤治疗。若热盛且痰多者，用清热化痰汤。对于重舌的外治法，可用桑白皮、僵蚕、头发灰，用醋调匀敷于舌下，使用金丹（见咽喉）吹入患处更为巧妙。内服方药包括黄连、犀角、山栀、丹皮、生地、木通、赤芍、麦冬、连翘、生甘草。若木舌肿胀严重，颜色像猪肝一样，满口胀塞，先在舌尖或两旁刺破出血，再观察舌下是否有如蝼蛄、卧蚕般的肿突，若有则刺出紫血，用棉花蘸甘草水润湿患处，用百草霜细研后以醋调匀敷于舌上下，或者与盐等分，用井花水调涂。凡是舌体肿胀，适宜刺破舌尖、舌面或两旁使其出血，只有舌下的廉泉穴属于肾经，需谨慎针刺，恐怕出血过多会导致失音。按：木舌中有不痛的，是因为痰湿盛于热邪所致。又有麻舌，是因火嘘痰沸导致麻木，或因血虚气涩也致麻木，原理详见“痹门”。舌强（舌体僵硬），舌肿必然导致强硬，即木舌不能柔软灵活的表现，可用牛黄散。另外可用蛇蜕烧存性，与全蝎等分，研为细末敷之。又有因痰涎阻滞筋脉，不能转运而导致强硬的。（详见中风门。）又有因热极燥血，不能濡养筋脉，拘急而强硬的，（详见中风门。）严重时甚至卷缩。舌卷缩，是肝经热极，血枯不能濡养筋脉，所以卷缩。又有伤寒直中阴经，寒邪甚盛导致筋脉收引，也会卷缩。并详见伤寒篇。然而《内经》说：邪气客居三焦之络，会出现喉痹、舌卷、口干、心烦。又说：大肠筋病，转筋、舌卷。由此可见，不止是肝一经如此，也不止是伤寒一证如此。风寒湿邪中伤导致的舌强卷缩，用小续命汤。（见中风。）挟有热邪者，用升麻汤加桔梗漱口，碧雪敷之。舌伸出不收，因热甚（纵长与肿大是一样的，所以都是热甚所致），用珠末、冰片等分敷之，内服黄芩、僵蚕、胆星、乌药、竹沥等，以去痰清热。伤寒热毒攻心，以及伤寒愈后不能调养摄护（阴阳易常有此症），与中毒、大惊、产后等情况都有发生。严重的舌头伸出数寸，用巴豆一枚，去油取霜，用纸捻卷好，纳入鼻中，舌头自然收回，这是治疗伤寒后不调摄者的方法。产后患者，用朱砂末敷舌，令其呈现产子状，由两名女子搀扶，然后在墙外悄悄堆叠盆盎，碰倒发出声响，声音传入耳中，舌头就收回了。其余情况，可用雄鸡冠血浸舌，或用冬青浓汁浸。舌纵（舌体松弛下垂）流涎，涎液从舌下廉泉穴流出，乃肾火盛而逼迫津液上出所致，可用神龟滋阴丸（见痿芩）、黄连、山栀、黄柏、竹沥、姜汁等治疗。舌干裂，用花粉散、泻心汤。舌生疮，用甘露饮。口舌生疮，身体疲倦、饮食减少，用清热补血汤。若无效，用补中益气汤（见气）加五味子。思虑太过，血伤火动者，用归脾汤（见血）加柴胡、栀子、丹皮。舌下生水泡，初起一个，逐渐增至七八枚，称为连珠疳，吹口疳药。（见口。）
The tongue is the sprout of the Heart. The Spleen meridian connects to the root of the tongue and scatters beneath it. The Kidney meridian flanks the root of the tongue. The Bladder and Sanjiao (Triple Burner) sinews both knot at the root of the tongue. The Liver meridian links to the root of the tongue.
Tongue coating is discussed in detail under the section "Four Diagnostic Methods: Inspecting the Tongue." Lingnu (bleeding from the tongue) is detailed under the "Blood" category. Swelling and pain of the tongue, where swelling beneath the tongue resembles a newly formed small tongue, is named Chongshe (double tongue). If the tongue is swollen, hard, and inflexible, it is named Mushe (wooden tongue). These conditions are all caused by accumulated heat in the Heart, Spleen, and Stomach meridians. Treatments include Liangge San (Cool the Diaphragm Powder), Zhizi Jinhua Tang (Gardenia Golden Flower Decoction), and Xuanshen Shengma Tang (Scrophulariae Radix and Cimicifugae Rhizoma Decoction). In cases with abundant phlegm due to heat, Qingre Huatan Tang (Clear Heat and Resolve Phlegm Decoction) is used. For external treatment of Chongshe, apply mulberry bark (Sangbai), silkworm (Jiangcan), and hair ash mixed with vinegar to the sublingual area; blowing Jin Dan (Golden Pill) into the lesion is even more effective. Internal medications include Coptidis Rhizoma (Huanglian), Cornu Rhinocerotis (Xijiao), Gardeniae Fructus (Shanzhi), Moutan Cortex (Danpi), Rehmanniae Radix (Shengdi), Akebia Caulis (Mutong), Paeoniae Radix Rubra (Chishao), Ophiopogonis Radix (Maidong), Forsythiae Fructus (Lianqiao), and Glycyrrhizae Radix et Rhizoma (Sheng Gancao). If Mushe is severely swollen with a color resembling pig liver and causing fullness and blockage in the mouth, prick the tip or sides of the tongue first to bleed. Then inspect if there are protrusions like mole crickets or silkworms under the tongue; if so, prick them to release purple blood. Moisten the area with cotton dipped in Licorice water, then apply finely ground Carbonis Herba (Baicaoshuang) mixed with vinegar to the upper and lower surfaces of the tongue, or mix equal parts with salt and well water (Jinghua Shui) for application. Generally, for tongue swelling, it is advisable to prick the tip, surface, or sides to induce bleeding. However, the Lianquan acupoint (Ren-23) beneath the tongue belongs to the Kidney meridian; pricking must be done cautiously to avoid excessive bleeding which may lead to aphonia. Note: Some cases of Mushe are painless, caused by phlegm-dampness overwhelming heat. There is also Ma She (numb tongue), caused by fire stirring up phlegm or by blood deficiency and qi stagnation; principles are detailed under the "Bi Syndrome" category. Tongue stiffness (She Jiang) occurs when tongue swelling leads to rigidity, i.e., the inability of Mushe to remain flexible. Niuhuang San (Calculus Bovis Powder) is used. Additionally, burn snake skin until carbonized but retaining its nature, mix equally with Scorpion (Quanxie), grind into fine powder, and apply. Stiffness can also result from phlegm-saliva obstructing the sinews, preventing movement (see Stroke category). It can also result from extreme heat drying blood, failing to nourish sinews, leading to spasms and stiffness (see Stroke category). Severe cases result in retraction. Tongue retraction is caused by extreme heat in the Liver meridian and blood depletion failing to nourish sinews. Direct transmission of cold pathogens to Yin meridians in Cold Damage diseases causes severe cold, drawing in sinews and causing retraction (see Cold Damage). However, the Classic states that when pathogens invade the collaterals of the Sanjiao, symptoms include throat obstruction, tongue retraction, dry mouth, and irritability. It also states that Large Intestine meridian pathology causes muscle twitching and tongue retraction. Thus, it is not limited to the Liver meridian alone, nor solely to Cold Damage patterns. For tongue stiffness and retraction caused by Wind-Cold-Dampness, Xiao Xuming Tang (Minor Continue Life Decoction) is used (see Stroke). If accompanied by heat, use Shengma Tang (Cimicifugae Decoction) with Platycodonis Radix (Jiegeng) for gargling, and Bixue (Green Snow) for external application. For tongue protrusion that cannot retract due to severe heat (protrusion and swelling share the same pathological basis of severe heat), apply Zhumo (Pearl End) and Borax (Bingpian) in equal parts externally. Internally, administer Scutellariae Radix (Huangqin), Bombyx Batryticatus (Jiangcan), Arisaematis Cum Bile (Danning), Linderae Radix (Wuyao), and Bamboo Sap (Zhuli) to resolve phlegm and clear heat. When Cold Damage heat-toxin attacks the Heart, or after recovery from Cold Damage due to improper care (common in Yin-Yang Exchange), or in cases of poisoning, great fright, or postpartum conditions, the tongue may protrude several inches. Use one Bean, Viciae Semen (Badou), remove oil to obtain frost, roll in paper twist, insert into nose; the tongue will naturally retract. This treats post-Cold Damage mismanagement. For postpartum cases, apply Cinnabar (Zhusha) powder to the tongue to simulate childbirth posture, have two women support the patient, then secretly stack pots outside the wall and knock them over to make noise; upon hearing the sound, the tongue retracts. Other methods include soaking the tongue in Rooster Comb Blood (Xiongji Guanxue) or Wintergreen Juice (Dongqing Nongzhi). Tongue laxity with salivation occurs when saliva flows from the Lianquan acupoint beneath the tongue, caused by excessive Kidney fire forcing fluids upward. Shen Gui Ziyin Wan (Divine Turtle Nourishing Yin Pill), Huanglian, Shanzhi, Huangbai, Zhuli, and Jiangzhi are applicable. Dry and cracked tongue is treated with Huafen San (Trichosanthis Radix Powder) and Xiexin Tang (Drain the Heart Decoction). Tongue ulcers are treated with Ganlu Yin (Sweet Dew Drink). Mouth and tongue ulcers with fatigue and poor appetite are treated with Qingre Buchi Tang (Clear Heat and Nourish Blood Decoction). If ineffective, use Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) with Wuweizi. For excessive worry damaging blood and stirring fire, use Guipi Tang (Restore the Spleen Decoction) with Chaihu, Shanzhi, and Danpi. Sublingual blisters starting as one and increasing to seven or eight are named Lianzhu Gan (String Pearl Caries); use Kougan Yao (Mouth Ulcer Medicine).