甘草（二两炙） 附子（大者一枚生用去皮破八片） 干姜（三两强人可四两）
上三味。以水三升。煮取一升二合。去滓。分温再服。其脉即出者愈。
后加减法。
面色赤者。加葱九茎。
葱味辛。以通阳气。
腹中痛者。去葱。加芍药二两。
芍药之酸。通寒。利腹中痛。为气不通也。
呕者。加生姜二两。
辛以散之。呕为气不散也。
咽痛者。去芍药。加桔梗一两。
咽中如结。加桔梗则能散之。
利止。脉不出者。去桔梗。加人参一两。
利止脉不出者。亡血也。加人参以补之。经曰。脉微而利。亡血也。四逆加人参汤
主之。脉病皆与方相应者。乃可服之。
王宇泰云。方与四逆汤同。但此倍干姜耳。
少阴病。四逆。其人或咳、或悸。或小便不利。或腹中痛。或泄利下重者。四逆散
主之。
四逆者。四肢不温也。伤寒邪在三阳。则手足必热。传到太阴。手足自温。至少阴。
则邪热渐深。故四肢逆而不温也。及至厥阴。则手足厥冷。是又甚于逆。四逆散。以散
传阴之热也。
甘草（炙味甘平） 枳实（破水渍炙干味苦寒） 柴胡（味苦寒） 芍药（味酸微寒）
上四味。各十分。捣筛白饮和。服方寸匕。日三服。
内经曰。热淫于内。佐以甘苦。以酸收之。以苦发之。枳实甘草之甘苦。以泄里热。
芍药之酸。以收阴气。柴胡之苦。以发表热。
后加减法。
咳者。加五味子。干姜。各五分。并主下痢。
肺寒气逆则咳。五味子之酸。收逆气。干姜之辛。散肺寒。并主下痢者。肺与大肠
为表里。上咳下痢。治则颇同。
悸者。加桂枝五分。
悸者。气虚而不能通行。心下筑筑然悸动也。桂犹圭也。引导阳气。若热以使。小
便不利者。加茯苓五分。
茯苓味甘而淡。用以渗泄。
腹中痛者。加附子一枚。炮令拆。
里虚。遇邪则痛。加附子以补虚。
泄利下重者。先以水五升。煮薤白三升。煮取三升。去滓。以散三方寸匕。内汤中。
煮取一升半。分温再服。
泄利下重者。下焦气滞也。加薤白以泄气滞。
论云。四肢者。诸阳之本。阳气不足。阴寒加之。阳气不相顺接。是致手足不温而
成四逆。此汤中发阳气。走散阴寒。温经暖肌。故以四逆名。此奇制之大剂也。四
逆属少阴。少阴者肾也。肾肝位远。非大剂不能达。内经曰。远而奇偶。制大其服。此
之谓也。
少阴病。下利。六七日咳而呕渴。心烦不得眠者。猪苓汤主之。
下利不渴者。里寒也。经曰。自利不渴者。属太阴。以其脏寒故也。此下利呕渴。知
非里寒。心烦不得眠。知胁热也。与猪苓汤渗泄小便。分别水谷。经曰。复不止。当利
其小便。此之谓欤。
少阴病。得之二三日。口燥咽干者。急下之。宜大承气汤。
伤寒传经五六日。邪传少阴。则口燥舌干而渴。为邪渐深也。今少阴病。得之二三
日。邪气未深入之时。便作口燥咽干者。是邪热已甚。肾水干也。急与大承气汤下之。
以全肾也。
少阴病。自利清水。色纯青。心不必痛。口干燥者。急下之。宜大承气汤。
少阴、肾水也。青、肝色也。自利色青。为肝邪乘肾。难经曰。从前来者为实邪。以
肾蕴实邪。必心下痛。口干燥也。与大承气汤。以下实邪。
少阴病。六七日。腹胀不大便者。急下之。宜大承气汤。
此少阴入腑也。六七日。少阴之邪入腑之时。阳明内热壅甚。腹满不大便也。阳明
病。土胜。肾水则干。急与大承气汤下之。以救肾水。
张兼善云。阳明与少阴。皆有急下之条。然而证虽不同。其入腑之理则一。是以皆
用大承气也。
王三阳云。少阴病。下利七六日。以下诸条。方是阳证传经之少阴也。
少阴病。脉沉者。急温之。宜四逆汤。
既吐且利。小便复利而大汗出。下利清谷。内寒外热。脉微欲绝者。不云急温。此
少阴病脉沉。而云急温者。彼虽寒甚。然而证已形见于外。治之则有成法。此初头脉沉。
未有形证。不知邪气所之。将发何病。是急与四逆汤温之。
少阴病。饮食入口则吐。心中温温欲吐。复不能吐。始得之。手足寒。脉弦迟者。此
胸中实。不可下也。当吐之。若膈上有寒饮干呕者。不可吐也。急温之。宜四逆汤。
伤寒表邪传里。至于少阴。少阴之脉。从肺出络心。注胸中。邪既留于胸中而不散
者。饮食入口则吐。心中温温欲吐。阳受气于胸中。邪既留于胸中。则阳气不得宣发于
外。是以始得之。手足寒。脉弦迟。此是胸中实。不可下而当吐。其膈上
有寒饮。亦使人心中温温而手足寒。吐则物出。呕则物不出。吐与呕别焉。胸中实。则
吐而物出。若膈上有寒饮。则但干呕而不吐也。此不可吐。可与四逆汤。以温其膈。
王三阳云。此少阴寒中阴经者也。俱未入于腑。
少阴病。下利。脉微涩。呕而汗出。必数更衣。反少者。当温其上。灸之。
脉微为亡阳。涩为亡血。下利呕而汗出。亡阳亡血也。津液不足。里有虚寒。必数
更衣。反少者。温其上。以助其阳也。灸之以消其阴。
甘草（二两，经蜜炙） 附子（大者一枚，生用，去皮，破成八片） 干姜（三两，体质强壮者可增至四两）
以上三味药。用水三升。煎煮至取汁一升二合。滤去药渣。分两次温服。如果脉搏随即恢复出现，即为痊愈。
后续加减法：
面色发红的，加葱九茎。
葱味辛，用来通达阳气。
腹中疼痛的，去掉葱，加芍药二两。
芍药的酸味，能通散寒气，缓解腹中疼痛，这是因为气机不通畅所致。
呕吐的，加生姜二两。
辛味能发散，呕吐是因为气机不能发散。
咽喉痛的，去掉芍药，加桔梗一两。
咽喉中有堵塞感，加入桔梗就能消散它。
腹泻停止但脉搏不出的，去掉桔梗，加人参一两。
腹泻停止但脉搏不出的，是血虚的表现。加入人参来补益。医经说：脉象微弱且腹泻，是亡血的表现。应当用四逆加人参汤主治。脉证与方剂相应的，才可以服用。
王宇泰说：此方与四逆汤相同，只是此处干姜加倍罢了。
少阴病，四肢厥冷，或者伴有咳嗽、心悸，或者小便不利，或者腹中疼痛，或者泄泻且肛门有下坠感的，用四逆散主治。
所谓“四逆”，是指四肢不温暖。伤寒邪气在太阳、阳明、少阳三阳经时，手足必然发热；传到太阴经时，手足自然温和；到了少阴经，则邪热逐渐深入，所以四肢逆冷而不温；及至厥阴经，则手足冰冷，这比“逆”更严重。四逆散，是用来疏散传入阴经的热邪。
甘草（蜜炙，味甘平） 枳实（破开，水浸后炒干，味苦寒） 柴胡（味苦寒） 芍药（味酸微寒）
以上四味药。各取十分，捣碎过筛，用白饮（米汤）调和，每次服用一方寸匕的药量。每日服用三次。
《内经》说：热邪蕴结于内，用甘苦之品辅助，用酸味收敛，用苦味发散。枳实和甘草的甘苦味，用来清泄里热；芍药的酸味，用来收敛阴气；柴胡的苦味，用来发表热。
后续加减法：
咳嗽的，加五味子、干姜，各五分。同时也主治痢疾。
肺气寒冷上逆则咳嗽。五味子的酸味，收敛逆气；干姜的辛味，散除肺寒。之所以也主治痢疾，是因为肺与大肠互为表里，上部的咳嗽和下部的痢疾，治疗原则大致相同。
心悸的，加桂枝五分。
心悸，是因为气虚而不能通行，心下部悸动不安。桂同圭，有引导阳气的作用，如同用火加热一样。
小便不利的，加茯苓五分。
茯苓味甘淡，用来渗湿利水。
腹中疼痛的，加附子一枚，炮制裂开。
里虚，遇到邪气就会疼痛，加附子来补虚。
泄泻且肛门有下坠感的，先用水五升，煮薤白三升，煮取三升，滤去药渣。将四逆散三方寸匕的药粉放入汤中，再煮取一升半，分两次温服。
泄泻且肛门有下坠感的，是下焦气机阻滞。加入薤白来泄除气滞。
《论》说：四肢是诸阳之本。阳气不足，阴寒侵袭，阳气不能顺接，导致手足不温而成四逆。此汤能发越阳气，走散阴寒，温经暖肌，所以命名为四逆。这是奇制的大剂量方剂。四逆属少阴，少阴即肾。肝肾位置较远，非大剂量药力不能到达。《内经》说：病位深远且药性有奇偶配合，就加大服药量。说的就是这个道理。
少阴病，腹泻，六七天以后出现咳嗽、呕吐、口渴、心烦不得睡眠的，用猪苓汤主治。
腹泻但不口渴的，是里寒。医经说：自发性腹泻且不口渴的，属于太阴，因为脏腑寒冷的缘故。此处腹泻、呕吐、口渴，知道不是里寒；心烦不得眠，知道是有热。给予猪苓汤渗湿利小便，分别水谷。医经说：如果腹泻仍不止，应当利小便。说的就是这个意思吧。
少阴病，得病二三天，口燥咽干的，应当急下，宜用大承气汤。
伤寒传经五六日，邪气传入少阴，则口燥舌干而渴，这是邪气逐渐深入。现在少阴病，得病仅二三天，邪气尚未深入之时，就出现口燥咽干，这是邪热已经很盛，肾水枯竭。急需给予大承气汤攻下，以保全肾水。
少阴病，自利清水，颜色纯青，心部不一定痛，口干燥的，应当急下，宜用大承气汤。
少阴对应肾水。青色对应肝色。自利颜色发青，是肝邪乘袭肾脏。《难经》说：从前来者为实邪。因为肾中蕴藏实邪，必定心下疼痛，口干燥。给予大承气汤，以攻下实邪。
少阴病，六七天，腹胀不大便的，应当急下，宜用大承气汤。
这是少阴病传入腑。六七天，是少阴邪气传入腑的时候，阳明内热壅盛，腹部胀满不大便。阳明病，土气胜，肾水就会干枯。急需给予大承气汤攻下，以救肾水。
张兼善说：阳明与少阴，都有急下的条文。然而证候虽然不同，其传入腑的道理是一致的。所以都用大承气汤。
王三阳说：少阴病，腹泻六七天的以下各条，才是阳证传经入里的少阴病。
少阴病，脉沉的，应当急温，宜用四逆汤。
既呕吐又腹泻，小便反而通畅且大汗出，腹泻完谷不化，内寒外热，脉微欲绝的，没有说急温。此处少阴病脉沉，却说急温，是因为彼证虽然寒甚，但症状已经显露在外，治疗则有定法。此处初起仅见脉沉，还没有显现症状，不知道邪气所在，将要发作什么病，所以急忙给予四逆汤温补。
少阴病，饮食入口即吐，心中烦闷想吐又吐不出来，刚得病时，手足寒冷，脉弦迟的，这是胸中实证，不可攻下，应当催吐。如果是膈上有寒饮导致干呕的，不可催吐，应当急温，宜用四逆汤。
伤寒表邪传入体内，至于少阴。少阴经脉，从肺出发联络心脏，注入胸中。邪气既然留滞于胸中不散，饮食入口就会呕吐，心中烦闷想吐。阳气受气于胸中，邪气留滞胸中，则阳气不能宣发于外，所以刚得病时，手足寒冷，脉弦迟。这是胸中实证，不可攻下而应当催吐。如果是膈上有寒饮，也会使人心中烦闷且手足寒冷。吐则是物出，呕则是物不出，吐与呕是不同的。胸中实证，则吐且物出；若膈上有寒饮，则仅干呕而不吐出实物。这种情况不可催吐，可给予四逆汤，以温煦膈部。
王三阳说：这是少阴寒邪中伤阴经的情况。都未传入腑。
少阴病，腹泻，脉微涩，呕吐且出汗，必定频繁上厕所，但排便量反而很少的，应当温其上部的穴位，并用艾灸治疗。
脉微是亡阳，脉涩是亡血。腹泻、呕吐且出汗，是亡阳亡血。津液不足，里有虚寒，必定频繁上厕所，但排便量反而少。温其上穴，以助其阳气。艾灸以消除阴寒。
Gancao (Licorice Root, two liang, honey-fried) Fuzi (Aconite Lateralis Radix Praeparata, one large piece, raw, peeled, broken into eight pieces) Ganjiang (Dried Ginger, three liang; four liang for robust individuals)
The above three ingredients. Add three sheng of water. Decoct to obtain one sheng and two he of liquid. Remove the dregs. Divide into two doses and take warm. If the pulse reappears, it indicates recovery.
Subsequent modifications:
If the face is red, add nine stalks of Congbai (Scallion White).
Congbai is pungent in flavor and serves to unblock Yang Qi.
If there is abdominal pain, remove Congbai and add Shaoyao (Peony Root), two liang.
Shaoyao's sour flavor helps to disperse cold and relieve abdominal pain, which is caused by Qi stagnation.
If there is vomiting, add Shengjiang (Fresh Ginger), two liang.
Pungency disperses; vomiting occurs due to failure of Qi to disperse.
If there is a sore throat, remove Shaoyao and add Jiegeng (Platycodon Root), one liang.
A sensation of obstruction in the throat can be dispersed by adding Jiegeng.
If diarrhea stops but the pulse does not appear, remove Jiegeng and add Renshen (Ginseng Root), one liang.
Diarrhea stopping with no pulse indicates blood depletion. Adding Renshen tonifies this. The Classics state: "A faint pulse with diarrhea indicates blood depletion." Si Ni Jia Renshen Tang (Four Reversal Plus Ginseng Decoction) should be used as the primary treatment. Only administer when the pulse and symptoms correspond appropriately with the formula.
Wang Yutai stated: This formula is identical to Si Ni Tang (Four Reversal Decoction), except that the dosage of Ganjiang (Dried Ginger) is doubled here.
In Shaoyin disease, characterized by Si Ni (cold extremities), where the patient may also have cough, palpitations, difficulty urinating, abdominal pain, or diarrhea with a sensation of heaviness in the rectum, Si Ni San (Four Reversal Powder) is indicated.
"Si Ni" refers to limbs that are not warm. When pathogenic factors from Cold Damage are in the Three Yang meridians, the hands and feet must be hot. When transmitted to Taiyin, the hands and feet become naturally warm. Upon reaching Shaoyin, the pathogenic heat deepens, causing the limbs to become cold and not warm. Upon reaching Jueyin, the hands and feet become icy cold, which is more severe than "Ni". Si Ni San is used to dissipate heat transmitted to the Yin meridians.
Gancao (Honey-fried, sweet and neutral) Zhishi (Immature Bitter Orange Fruit, broken, soaked in water and stir-fried dry, bitter and cold) Chaihu (Bupleurum Root, bitter and cold) Shaoyao (Peony Root, sour and slightly cold)
The above four ingredients. Each taken in ten parts. Pound and sieve, mix with Baiyin (rice water decoction). Take one fangcun bi (a square-inch measure) per dose. Take three times daily.
The Neijing states: "When heat floods internally, assist with sweet and bitter agents; use sour to collect/astringe, and bitter to vent/disperse." The sweet and bitter properties of Zhishi and Gancao clear and drain interior heat. The sour property of Shaoyao collects/astringes Yin Qi. The bitter property of Chaihu vents exterior heat.
Subsequent modifications:
If there is cough, add Wuweizi (Schisandra Berry) and Ganjiang (Dried Ginger), each five fen. These also treat dysentery.
Cold Qi in the Lung causing rebellious Qi leads to cough. The sourness of Wuweizi astringes rebellious Qi; the pungency of Ganjiang disperses Lung cold. They also treat dysentery because the Lung and Large Intestine are exterior-interior pairs; treating upper cough and lower dysentery follows similar principles.
If there are palpitations, add Guizhi (Cinnamon Twig), five fen.
Palpitations occur due to Qi deficiency failing to circulate smoothly, causing a thumping sensation below the heart. "Gui" resembles "Gui" (jade tablet), guiding Yang Qi, much like using heat to drive away cold.
If there is difficulty urinating, add Fuling (Poria), five fen.
Fuling has a sweet and bland flavor, used to leach out dampness.
If there is abdominal pain, add one Fuzi (Aconite Lateralis Radix Praeparata), roasted until cracked.
Interior deficiency causes pain upon encountering pathogens; adding Fuzi tonifies deficiency.
If there is diarrhea with a sensation of heaviness in the rectum, first boil Xiebai (Allium Macrostemon Bulb) in five sheng of water until reduced to three sheng. Remove dregs. Add three fangcun bi of the powder to the decoction. Boil until reduced to one sheng and half. Divide into two doses and take warm.
Diarrhea with rectal heaviness indicates Qi stagnation in the Lower Jiao. Adding Xiebai drains Qi stagnation.
The Treatise states: "The four limbs are the root of all Yang." Insufficiency of Yang Qi allows Yin-Cold to invade. When Yang Qi fails to connect smoothly, the hands and feet become cold, resulting in Si Ni. This formula promotes Yang Qi, scatters Yin-Cold, warms the channels, and warms the muscles, hence named Si Ni. This is a large-dose prescription of unique formulation. Si Ni belongs to Shaoyin, which corresponds to the Kidney. The Liver and Kidney are distant organs; only large doses can reach them. The Neijing states: "When the location is distant and the combination is odd/even, increase the dosage." This refers to such cases.
In Shaoyin disease, if there is diarrhea, followed after six or seven days by cough, vomiting, thirst, irritability, and inability to sleep, Zhu Ling Tang (Polyporus Decoction) is indicated.
Diarrhea without thirst indicates interior cold. The Classics state: "Spontaneous diarrhea without thirst belongs to Taiyin, due to organ cold." Here, diarrhea, vomiting, and thirst indicate it is not interior cold. Irritability and insomnia indicate heat. Administer Zhu Ling Tang to promote diuresis and separate fluids from food grains. The Classics state: "If it does not stop, promote urination." This is what is meant.
In Shaoyin disease, if dry mouth and dry throat appear within two or three days of onset, urgent purgation is required. Da Cheng Qi Tang (Major Order the Qi Decoction) is appropriate.
After five or six days of transmission in Cold Damage, when pathogens enter Shaoyin, dry mouth, tongue, and thirst occur, indicating deepening pathogens. Now, in Shaoyin disease, if dry mouth and throat appear within two or three days, while pathogens have not yet deeply invaded, this indicates extreme pathogenic heat and exhaustion of Kidney Water. Urgently administer Da Cheng Qi Tang to purge and preserve Kidney Water.
In Shaoyin disease, if there is spontaneous passage of clear green stool, without necessarily abdominal pain, but with dry mouth, urgent purgation is required. Da Cheng Qi Tang is appropriate.
Shaoyin corresponds to Kidney Water. Green corresponds to Liver color. Clear green stool indicates Liver Pathogen attacking the Kidney. The Nanjing states: "Coming from the preceding element is Excess Pathogen." Because the Kidney harbors excess pathogens, there must be subcostal pain and dry mouth. Administer Da Cheng Qi Tang to purge excess pathogens.
In Shaoyin disease, if abdominal distension and constipation occur after six or seven days, urgent purgation is required. Da Cheng Qi Tang is appropriate.
This is Shaoyin transmitting to the Fu organs. At six or seven days, Shaoyin pathogens enter the Fu organs. Yangming interior heat becomes severely congested, causing abdominal fullness and constipation. In Yangming disease, Earth overcomes Water, drying Kidney Water. Urgently administer Da Cheng Qi Tang to purge and save Kidney Water.
Zhang Jianshan stated: Both Yangming and Shaoyin have clauses regarding urgent purgation. Although the syndromes differ, the principle of transmitting to the Fu organs is the same. Therefore, Da Cheng Qi Tang is used in both.
Wang Sanyang stated: Regarding the following clauses in Shaoyin disease with diarrhea for six or seven days, these represent Shaoyin disease resulting from the transmission of Yang syndromes.
In Shaoyin disease, if the pulse is deep, urgent warming is required. Si Ni Tang (Four Reversal Decoction) is appropriate.
In cases of vomiting and diarrhea, with frequent urination, profuse sweating, passing undigested food, interior cold with exterior heat, and a faint pulse nearly imperceptible, urgent warming is not specified. Here, in Shaoyin disease with a deep pulse, urgent warming is specified because, although the other case involves severe cold, the symptoms are already manifest externally, allowing for established treatment methods. Here, initially only a deep pulse is seen, without manifest symptoms, making it unknown where the pathogen lies or what disease will develop. Thus, urgently administer Si Ni Tang to warm.
In Shaoyin disease, if food is vomited immediately upon entering the mouth, accompanied by a feeling of nausea and desire to vomit but inability to do so, and upon initial onset, the hands and feet are cold with a wiry and slow pulse, this indicates Excess in the Chest. Purging is contraindicated; emesis should be induced. If there is cold-fluid retention above the diaphragm causing dry retching, emesis is contraindicated; urgent warming is required. Si Ni Tang is appropriate.
When exterior pathogens from Cold Damage transmit inward to Shaoyin, since the Shaoyin meridian originates from the Lung, connects to the Heart, and enters the Chest, pathogenic retention in the chest prevents the expulsion of food, causing vomiting and nausea. Yang Qi receives Qi in the chest; retention prevents its outward dissemination, causing cold hands and feet and a wiry-slow pulse upon onset. This is Chest Excess, requiring emesis rather than purging. Cold-fluid retention above the diaphragm also causes nausea and cold hands. Vomiting expels material; retching does not. They are distinct. Chest Excess results in vomiting with material expulsion. Diaphragmatic cold-fluid retention results only in dry retching without material expulsion. Emesis is contraindicated here; Si Ni Tang should be given to warm the diaphragm.
Wang Sanyang stated: This represents Cold damaging the Yin meridians in Shaoyin. Neither has entered the Fu organs.
In Shaoyin disease, if there is diarrhea with a faint and choppy pulse, vomiting, sweating, frequent defecation attempts but small volume, warming the upper body points and moxibustion are indicated.
A faint pulse indicates loss of Yang; a choppy pulse indicates loss of Blood. Diarrhea, vomiting, and sweating indicate loss of Yang and Blood. Insufficient fluids and interior deficiency-cold lead to frequent defecation attempts with small volume. Warming the upper points assists Yang. Moxibustion eliminates Yin-Cold.