能引水气上升，滑石体质重坠，能引火气下降，水升火降，得既济之理矣。且猪苓、阿胶，黑色通肾，理少阴
之本；茯苓、滑石，白色通肺，滋少阴之源；泽泻、阿胶，咸先入肾，培少阴之体；二苓、滑石，淡渗膀胱，
利少阴之用。五味皆甘淡，得土中冲和之气，是水位之下，土气承之也。五物皆润下，皆滋阴益气之品，是君
火之下，阴精承之也。以此滋阴利水而升津，诸症自平矣。
四逆散∶
柴胡 枳实 芍药 甘草
少阴病四逆，泄利下重，其人或咳或悸，或小便不利，或腹中痛者，此方主之。少阴为水火同处之脏，水火
不和，则阴阳不相顺接。四肢为阴阳之会，故厥冷四逆，有寒热之分，胃阳不敷于四肢为寒厥，阳邪内扰于阴
分为热厥。然四肢不温，故厥者必利，先审泻利之寒热，而四逆之寒热判矣。下利清谷为寒，当用姜、附壮元
阳之本；泄泻下重为热，故用白芍、枳实酸苦涌泄之品以清之。不用芩、连者，以病于阴而热在下焦也。更用
柴胡之苦平者，以升散之，令阴火得以四达。佐甘草之甘凉，以缓其下重。合而为散，散其实热也。用白饮和
服，中气和而四肢之阴阳自接，三焦之热自平矣。此症以泄利下重，知少阴之阳邪内扰于阴，四逆即非寒症矣。
四逆皆少阴枢机无主，升降不利所致，只宜治下重，不须兼治诸症也。仲景因有四逆症，欲以别于四逆汤，故
以四逆散名之。本方有咳者，加五味、干姜，悸者。加桂枝，腹痛加附子，泄利下重加薤白，俱非泄利下重所
宜。且五味、姜、桂加五分，于附子加一枚，薤白三升，何多寡不同若是？且以散只服方寸匕，恐不济此症，
此后人附会可知也。
猪肤汤∶
猪肤 白蜜 白粉
少阴病多下利，以下焦之虚也。阴虚则阳无所附，故下焦虚寒者，反见上焦之实热。少阴脉循喉咙，挟舌
本，其支者，出络心，注胸中。凡肾精不足，肾火不藏，必循经上走于阳分也。咽痛胸满心烦者，因阴并于下，
而阳并于上，承不上承于心，火不下交于肾，此未济之象。猪为水畜，而津液在肤，取其肤以治上焦虚浮之火，
和白蜜、白粉之甘，泻心润肺而和脾。滋化原，培母气，水升火降，上热下行，虚阳得归其部，不治利而利自
止矣。三味皆食物，不藉于草，所谓随手拈来，尽是道矣。
甘草汤∶
甘草
桔梗汤∶
甘草 桔梗
半夏汤∶
半夏 桂枝 甘草
苦酒汤∶
半夏 鸡子白 苦酒
四方皆因少阴咽痛而设也。少阴之脉循喉咙，挟舌本，故有咽痛症。若因于他症而咽痛者，不必治其咽。
如脉阴阳俱紧，反汗出而吐利者，此亡阳也。只回其阳，则吐利止而咽痛自除。如下利而胸满心烦者，是下焦虚
而上焦热也。升水降火，上下和调而痛自止。若无他症而但咽痛者，又有寒热之别。见于二三日，是阴火上冲，
可与甘草汤，甘凉泻火以缓其热。不瘥者，配以桔梗，兼辛以散之，所谓奇之不去而偶之也。二方为正治之轻
剂，以少阴为阴中之阴，脉微细而但欲寐，不得用苦寒之剂也。若其阴症似阳，恶寒而欲吐者，非甘、桔所能
疗，当用半夏之辛温，散其上逆之邪，桂枝之甘温，散其阴寒之气，缓以甘草之甘平，和以白饮之谷味，或为
散，或为汤，随病之意也。如咽中因痛而且伤，生疮不能言，语声不出者，不得即认为热症。必因呕而咽痛，
胸中之痰饮未散，仍用半夏之辛温，取苦酒之酸以敛疮，鸡子白之清以发声。且三味相合，而半夏减辛烈之猛，
苦酒缓收敛之骤，取鸡子白之润滋其咽喉，又不令泥痰饮于胸膈也。故其法以鸡子连壳置刀环中，安火上，只
三沸即去滓，此意在略见火气，不欲尽出半夏之味也明矣。二方皆少少含咽，是从治缓剂。按鸡卵法太极之形，
含阴阳两气，其黄走血分，故心烦不卧者用之。此仲景用药法象之义也。
上少阴七方，皆凉解法，后二方，皆温补法。
能够引导水气上升，滑石质地沉重下坠，能够引导火气下降，水升火降，便符合了“既济”（水火相交）的道理。况且猪苓、阿胶，色黑入通于肾，调理少阴的根本；茯苓、滑石，色白入通于肺，滋养少阴的源头；泽泻、阿胶，味咸先入于肾，培补少阴的本体；猪苓、茯苓与滑石，味淡渗利膀胱，发挥少阴的作用。这五味药皆具甘淡之性，得土中冲和之气，这是水位之下，有土气来承接它。这五物皆具润下之性，都是滋阴益气的药物，这是君火之下，有阴精来承接它。用这些药物来滋阴利水并提升津液，各种症状自然平息。
少阴病出现四肢厥冷，伴有腹泻且肛门重坠感，或者患者咳嗽、心悸，或者小便不利，或者腹中疼痛的，此方主治。少阴是水和火共同所在的脏腑，水火不协调，则阴阳不能顺利交接。四肢是阴阳交汇之处，所以四肢厥冷有寒证和热证之分，胃阳不能温煦四肢称为寒厥，阳邪在内扰乱阴分称为热厥。然而四肢不温暖，所以发生厥逆必然伴有泄利，先审察泄利的寒热性质，那么四肢厥冷的寒热性质就判断清楚了。大便清稀夹杂未消化食物属于寒证，应当使用干姜、附子来壮元阳之本；腹泻且肛门重坠属于热证，所以使用白芍、枳实这类酸苦涌泄的药物来清热。不用黄芩、黄连的原因，是因为病在阴分，且热在下焦。再用柴胡的苦平之性，来升散郁结，使阴火得以向四周通达。佐以甘草的甘凉，来缓解肛门重坠感。合起来制成散剂，是为了疏散实热。用米汤调和服用，中气调和而四肢的阴阳自然相接，三焦的热邪自然平息。这个症状通过腹泻肛门重坠，可知是少阴的阳邪内扰于阴分，此时的四肢厥冷就不是寒证了。所有的四逆症都是由于少阴枢机运转无主，升降不利所致，只适宜治疗肛门重坠，不需要兼治其他症状。张仲景因为存在四逆症，想要将其与四逆汤区别开来，所以将此方命名为四逆散。原方中有咳嗽的，加五味子、干姜；有心悸的，加桂枝；有腹痛的，加附子；有腹泻肛门重坠的，加薤白，这些加减法都不适合用于单纯的腹泻肛门重坠证。况且五味子、干姜、桂枝各加五分，附子加一枚，薤白加三升，为什么用量差异如此之大？而且原方散剂每次只服方寸匕，恐怕不足以应对这些复杂的症状，这显然是后人附会添加的，可以由此知晓。
少阴病多伴有腹泻，这是由于下焦虚损。阴虚则阳气无所依附，所以下焦虚寒的人，反而会出现上焦的实热。少阴经脉循行经过喉咙，挟持舌根，其支脉出来联络心脏，注入胸中。凡是肾精不足，肾火不能潜藏，必定沿着经脉向上走到阳分。出现咽痛、胸满、心烦的症状，是因为阴气并于下，阳气并于上，心火不能下行交于肾，肾水不能上行承于心，这是“未济”（水火不交）的现象。猪是水畜，津液存在于皮肤，取其猪肤来治疗上焦虚浮之火，配合白蜜、白粉的甘味，泻心火、润肺燥并调和脾胃。滋养化源，培补母气，使水升火降，上焦之热下行，虚阳得以回归本位，不直接治疗腹泻而腹泻自然停止。这三味都是食物，不借助草药，正所谓随手拈来，尽是大道。
以上四方都是针对少阴病咽痛而设立的。少阴经脉循行经过喉咙，挟持舌根，所以会有咽痛的症状。如果是因其他病症引起的咽痛，不必专门治疗咽痛。例如脉象阴阳俱紧，反而出汗并伴有呕吐腹泻的，这是亡阳证。只需回阳救逆，那么呕吐腹泻停止而咽痛自然消除。如果是腹泻且胸满心烦的，这是下焦虚而上焦热。提升水气，下降火气，上下调和而疼痛自然停止。如果没有其他症状只是单纯咽痛的，又有寒证和热证的区别。发病在两三天内的，是阴火上冲，可以给甘草汤，利用其甘凉之性泻火以缓解热势。如果不好转，配合桔梗，兼用辛味以发散，这就是所谓“单剂无效改用双剂”的方法。这两方是正治法的轻剂，因为少阴是阴中之阴，脉象微细且只想睡觉，不能使用苦寒的药物。如果是阴证似阳，恶寒且想吐的，不是甘草、桔梗所能治疗的，应当使用半夏的辛温，来散其上逆之邪，桂枝的甘温，来散其阴寒之气，再缓用甘草的甘平，配合白饮的谷味，或者做成散剂，或者做成汤剂，随病情而定。如果咽喉因疼痛而受伤，生疮导致不能说话，声音发不出来的，不能立即认为是热证。必定是因为呕吐导致咽痛，胸中的痰饮尚未消散，仍需用半夏的辛温，取苦酒的酸味来收敛疮口，取鸡蛋清的清凉来发声。况且这三味药相合，半夏减少了辛烈的猛烈，苦酒减缓了收敛的急促，取鸡蛋清的滋润来滋养咽喉，又不让痰饮阻滞于胸膈。所以它的制法是连壳将鸡蛋放在刀环中，置于火上，煮到刚沸腾三次就去掉渣滓，这意在略微见火气，不想完全煮出半夏的味道，这是很明显的。这两方都是少量含咽，是从治法的缓剂。按鸡蛋的形状像太极之形，包含阴阳两气，蛋黄走血分，所以对于心烦不能卧的患者使用。这是张仲景用药的法象意义。
上述少阴病的七方，前五个都是凉解法，后两个都是温补法。
It can guide the Qi of water to ascend, while Talcum (Huashi, 滑石), being heavy and dense in texture, can guide the Qi of fire to descend. When water ascends and fire descends, the principle of Ji Ji (Ji Ji, Hexagram 63: After Completion/Water over Fire) is achieved. Furthermore, Polyporus (Zuling, 猪苓) and Donkey-hide Gelatin (Ejiao, 阿胶), with their black color, communicate with the Kidney, regulating the root of Shaoyin (Shaoyin, Lesser Yin); Poria (Fuling, 茯苓) and Talcum (Huashi, 滑石), with their white color, communicate with the Lung, nourishing the source of Shaoyin; Alisma (Zexie, 泽泻) and Donkey-hide Gelatin (Ejiao, 阿胶), with their salty taste, enter the Kidney first, cultivating the substance of Shaoyin; Polyporus (Zuling, 猪苓), Poria (Fuling, 茯苓), and Talcum (Huashi, 滑shi, 滑石), with their bland taste, promote diuresis in the Bladder, facilitating the function of Shaoyin. These five ingredients all possess sweet and bland properties, obtaining the harmonious Qi of Earth; this represents Earth Qi supporting below the position of Water. All five substances have a moistening and descending nature, serving as agents that nourish Yin and benefit Qi; this represents Yin Essence supporting below the Sovereign Fire. By using these to nourish Yin, promote diuresis, and elevate body fluids, various symptoms will naturally subside.
Sini San (Four Reversal Powder):
Bupleuri Radix (Chaihu, 柴胡), Immature Bitter Orange (Zhishi, 枳实), White Peony Root (Baishao, 芍药), Licorice Root (Gancao, 甘草)
In Shaoyin disease presenting with cold extremities (Jue Ni, 厥逆), diarrhea with a sensation of heaviness in the anus, or accompanied by cough, palpitations, difficult urination, or abdominal pain, this formula is indicated. Shaoyin is the zang organ where Water and Fire coexist. If Water and Fire are disharmonious, Yin and Yang cannot smoothly connect. The limbs are the meeting place of Yin and Yang; thus, cold extremities can be classified into cold syndromes and heat syndromes. When Stomach Yang fails to warm the limbs, it is called Cold Jue (Han Jue, 寒厥); when Yang pathogenic factors internally disturb the Yin aspect, it is called Heat Jue (Re Jue, 热厥). However, since the limbs are not warm, any case of Jue must involve diarrhea. By first examining whether the diarrhea is cold or heat, the nature of the cold extremities becomes clear. Diarrhea with undigested food indicates a cold syndrome, requiring Ginger (Shengjiang, 生姜/干姜) and Aconite (Fuzi, 附子) to strengthen the root of Primordial Yang. Diarrhea with anal heaviness indicates a heat syndrome, hence White Peony Root (Baishao, 芍药) and Immature Bitter Orange (Zhishi, 枳实)—agents with sour and bitter tastes that induce vomiting and purging—are used to clear the heat. Scutellaria (Huangqin, 黄芩) and Coptis (Huanglian, 黄连) are not used because the pathology lies in the Yin aspect, with heat located in the Lower Jiao. Additionally, Bupleuri Radix (Chaihu, 柴胡) with its bitter and neutral nature is used to ascend and disperse, allowing the Minister Fire to spread throughout. Licorice Root (Gancao, 甘草) with its sweet and cool nature is added to alleviate the anal heaviness. Combined as a powder, it disperses excess heat. Taken with rice water, the Middle Qi harmonizes, allowing Yin and Yang in the limbs to reconnect, and the heat in the Three Jiao naturally subsides. From the symptom of diarrhea with anal heaviness, we know that Shaoyin's Yang pathogenic factor is disturbing the Yin; thus, the cold extremities are not due to a cold syndrome. All cases of Jue result from the failure of Shaoyin's pivot mechanism to govern, leading to impaired ascending and descending. Treatment should focus solely on relieving the anal heaviness, without needing to address other symptoms simultaneously. Zhang Zhongjing named this Sini San to distinguish it from Sini Tang (Four Reversal Decoction), given the presence of Jue symptoms. For those with cough, add Schisandra (Wuweizi, 五味子) and Dried Ginger (Ganjiang, 干姜); for palpitations, add Cinnamon Twig (Guizhi, 桂枝); for abdominal pain, add Aconite (Fuzi, 附子); for diarrhea with anal heaviness, add Chinese Leek Bulb (Xiebai, 薤白). These modifications are not suitable for simple diarrhea with anal heaviness. Moreover, why do the dosages vary so significantly—Schisandra, Dried Ginger, and Cinnamon Twig added in small amounts (5 fen), Aconite added as one piece, and Chinese Leek Bulb added in large quantities (3 sheng)? Given that the original powder dosage is only one cun bi (square inch spoonful), it would likely be insufficient for such complex conditions. This clearly indicates later interpolations.
Zhufu Tang (Pig Skin Decoction):
Pig Skin (Zhufu, 猪肤), White Honey (Baimi, 白蜜), Rice Flour (Baifen, 白粉)
Shaoyin disease often involves diarrhea due to deficiency in the Lower Jiao. When Yin is deficient, Yang has no anchor; thus, individuals with Lower Jiao deficiency-cold may paradoxically exhibit Upper Jiao excess-heat. The Shaoyin meridian runs along the throat and flanks the base of the tongue; its branch emerges to connect with the Heart and enters the chest. Whenever Kidney Essence is insufficient and Kidney Fire fails to store, it necessarily travels upward along the meridian to the Yang aspects. Symptoms such as sore throat, chest fullness, and irritability arise because Yin congregates below and Yang congregates above; Heart Fire fails to descend to interact with the Kidney, and Kidney Water fails to ascend to support the Heart, representing the state of Wei Ji (Wei Ji, Hexagram 64: Before Completion/Fire over Water). The pig is an aquatic animal, and its moisture resides in the skin. Using pig skin treats floating fire in the Upper Jiao, combined with the sweetness of white honey and rice flour to drain Heart Fire, moisten the Lungs, and harmonize the Spleen. It nourishes the source of transformation, cultivates the Mother Qi (Kidney nourishing Liver/Lung via Five Elements logic, or generally strengthening the root), promotes water ascent and fire descent, directs upper heat downward, and allows deficient Yang to return to its proper location. Diarrhea stops spontaneously without direct treatment. These three ingredients are foods, not herbs, illustrating that the Dao is found in everyday things.
Gancao Tang (Licorice Decoction):
Licorice Root (Gancao, 甘草)
Jiegeng Tang (Platycodon Decoction):
Licorice Root (Gancao, 甘草), Platycodon Root (Jiegeng, 桔梗)
Banxia Tang (Pinellia Decoction):
Pinellia Rhizome (Banxia, 半夏), Cinnamon Twig (Guizhi, 桂枝), Licorice Root (Gancao, 甘草)
Kuju Tang (Vinegar Decoction):
Pinellia Rhizome (Banxia, 半夏), Egg White (Jizi Bai, 鸡子白), Vinegar (Ku Jiu, 苦酒)
The above four formulas are all designed for Shaoyin sore throat. Since the Shaoyin meridian runs along the throat and flanks the base of the tongue, sore throat occurs. If sore throat arises from other diseases, it need not be treated directly. For example, if the pulse is tight at both Cun and Chi positions, yet sweating occurs accompanied by vomiting and diarrhea, this indicates collapse of Yang (Wang Yang, 亡阳). Only by restoring Yang will vomiting and diarrhea cease, and the sore throat resolve. If diarrhea is accompanied by chest fullness and irritability, this indicates Lower Jiao deficiency and Upper Jiao heat. Ascending Water and descending Fire harmonizes the upper and lower, stopping the pain. If there are no other symptoms and only sore throat exists, it must be differentiated into cold and heat. Appearing within two to three days, it suggests Minister Fire rushing upward; Gancao Tang can be given, using its sweet-cool nature to drain fire and relieve heat. If ineffective, Platycodon Root (Jiegeng, 桔梗) is added to combine with acridity for dispersion, following the principle of "if single prescription fails, use double." These two formulas are mild agents for direct treatment. Since Shaoyin is Yin within Yin, with fine pulses and drowsiness, bitter-cold agents are contraindicated. If Yin syndrome mimics Yang, with aversion to cold and desire to vomit, Gancao and Jiegeng are ineffective. Instead, Pinellia Rhizome (Banxia, 半夏) with its acrid-warm nature disperses rebellious pathogens; Cinnamon Twig (Guizhi, 桂枝) with its sweet-warm nature disperses Yin-cold; Licorice Root (Gancao, 甘草) with its sweet-neutral nature, combined with rice water, forms either a powder or decoction according to the disease's needs. If the throat is injured by pain, forming ulcers and causing loss of voice, it should not be immediately diagnosed as heat. It likely results from vomiting causing throat pain, with phlegm-fluids remaining in the chest. Pinellia Rhizome (Banxia, 半夏) with acrid-warm nature is still used; Vinegar (Ku Jiu, 苦酒) with sour nature astringes ulcers; Egg White (Jizi Bai, 鸡子白) with cooling nature restores voice. The combination reduces Pinellia's harshness, moderates Vinegar's astringency, uses Egg White's moisture to nourish the throat, and prevents phlegm-fluids from obstructing the chest-diaphragm. The preparation method involves placing the egg in a knife ring over fire, boiling only three times before straining. This intent is to slightly expose it to heat without fully extracting Pinellia's flavor. These two formulas are taken by slowly holding and swallowing, representing gentle treatment from the side. The egg resembles the Taiji form, containing both Yin and Yang Qi; the yolk enters the Blood aspect, hence used for irritability and insomnia. This illustrates Zhang Zhongjing's symbolic use of medicinal properties.
The seven formulas for Shaoyin listed above: the first five employ cooling and resolving methods, while the last two employ warming and tonifying methods.