少阴一经。兼水火二气。寒热杂居。故为病不可捉摹。其寒也症类太阴。其热也症似太阳。故仲景以微细之病脉。
欲寐之病情为提纲。立法于象外。使人求法于病中。凡症之寒热之真假。仿此义以推之。其阴阳虚实见矣。五经提纲。
皆是邪气盛则实。惟少阴提纲。是指正气夺则虚者。以少阴为人身之本也。然邪气之盛。亦因正气之虚。故五经皆有可
温可补症。正气之夺。亦因邪气之盛。故少阴亦有汗吐下症。要知邪气盛。而正气已虚者。固本即以逐邪。正不甚虚。
而邪气实者。逐邪正所以护正。此大法也。
少阳为阳枢。少阴为阴枢。弦为木象。弦而细者。是阳之少也。微为水象。微而细者。是阴之少也。此脉气之相似。
卫气行阳则寤。行阴则寐。其行阳二十五度。常从足少阴之分间行脏腑。少阴病。则枢机不利。故欲寐也。与少阳喜呕
者同。呕者主出。阳主外也。寐者主入。阴主内也。喜呕是不得呕。欲寐是不得寐。皆在病患意中。得枢机之象如此。
少阴脉微。不可发汗。亡阳故也。脉细沉数。病为在里。不可发汗。然可汗之机。亦见于此。夫微为无阳。数则有
复阳矣。须审其病为在里而禁汗。不得拘沉为在里而不发汗也。发汗脉沉者。是病为在表。以无里症。故可发汗。若脉
浮而迟。表热里寒。下利清谷。是迟而无阳。病为在里。又不得以浮为在表。而发汗矣。要知阴中有阳。沉亦可汗。阳
中有阴。浮亦当温。若八九日。一身手足本热。是自里达表。阳盛阴虚。法当滋阴。又与二三日无里症者不侔。
太阴是阳明之里。阳明不恶寒。故太阴虽吐利腹痛。而无恶寒症。少阴是太阳之里。太阳恶寒。故少阴吐利必恶寒。
阴从阳也。太阴手足温者必暴烦下利而自愈。是太阴藉胃脘之阳。少阴吐利。亦必手足温者可治。手足厥者不治。是下
焦
之虚寒。既侵迫于中宫。而胃脘之阳。仍得敷于四末。始知先天之元阳。仍赖后天之胃气培植也。
太阳是少阴之标。太阴是少阴之本。少阴阴虚。则移热于膀胱。故一身手足尽热而便血。从标也。少阴阳虚。则移
寒于脾而吐利。从本也。
少阴传阳。症有二。六七日腹胀不大便者。是传阳明。脏气实则还之腑也。八九日一身手足尽热者。是传太阳。阴
出之阳。下利极而上也。
热在膀胱而便血。亦脏病传腑。此阴乘阳也。然气病而伤血。又阳乘阴也。亦见少阴中枢之象。此是自阴转阳。与
太阳热结膀胱。血自下者。见症同而病因异。少阴病脉紧。至七八日。自下利。脉暴微。手足反温。脉紧反去者。虽烦
利必自愈。此亦是脾家实。露出太阳底板。故得与太阴。七八日暴烦下利自止同。盖少阴来复之。阳微。则转属太阴而
秽腐自去。盛则转属阳明而糟粕不传。郁则内实而入阳明大府广肠之区。横则外达而遍太阳内外盛血之部。要知紧脉转
微。是复少阴本脉。故转太阴而自解。脉沉细数。是兼阳脉。故入阳经而为患。然热虽甚不死。亦阴自阳则解之变局也。
六经皆有烦躁。而少阴更甚者。以其阴之虚也。盖阳盛则烦。阴极则躁。烦属气。躁属形。烦发于内。躁见于外。是形
从气动也。先躁而后烦。是气为形役也。不躁而时自烦。是阳和渐回。故可治。不烦而躁。是五脏之阳已竭。惟魄独居。
故死。故少阴以烦为生机。躁为死兆。
伤寒以阳为主。不特阴症见阳脉者生。亦阴病见阳症者可治也。凡蜷卧四逆。吐利交作。纯阴无阳之症。全赖一阳
来复。故反烦者可治。手足反温者。反发热者不死。
太阳少阴。皆有身痛骨节痛之表。水气为患之里。太阳则脉浮紧而身发热。用麻黄汤发汗。是振营卫之阳以和阴也。
少阴之脉沉而手足寒。用附子汤温补。是扶坎中之阳以配阴也。太阳之水属上焦。小青龙汗而发之。阳水当从外散也。
少阴之水属下焦。真武汤温而利之。阴水当从下泄也。阴阳俱紧。与太阳伤寒相似。夫紧脉为寒。当属少阴。然病发于
阴不当有汗。反汗出者。阴极似阳。阳虚不能藏精所致也。亡阳之前。已先亡阴矣。阳无所根据。故咽痛呕吐。见阳虚
之不归。阴不能藏。故下利不止。见真阴之欲脱也。则附子汤。用三白以滋阴。参附以回阳。为少阴反本还元之剂。
肾主五液。入以为汗。少阴受病。液不上升。所以阴不得有汗。仲景治少阴之表。于麻黄细辛中加附子。是升阳液
而为汗也。若真阴为邪热所逼。则水随火越。故反汗出。仲景治少阴之里。附子汤中任人参。是补肾液而止汗也。脉阴
阳俱紧。口中气出条。是少阴经文。王氏集之脉法中。故诸家议论不一。夫少阴脉络。肺主鼻。故鼻中涕出。少阴脉络
舌本。故舌上苔滑。少阴大络。注诸络以温足胫。故足冷。此症不名亡阳者。因不汗出。内不吐利也。口中气出。唇口
燥干。鼻中涕出。此为内热。阴阳脉紧。舌上苔滑。蜷卧足冷。又是内寒。此少阴为枢。故见寒热相持之症。而口舌唇
鼻之半表半里。恰与少阳之口苦。咽干。目眩。相应也。勿妄治者。恐阴阳相持。苟清火温补等法。用之不当。宁静
以待之。至七日来复。微发热。手足温。是阴得阳之解也。故八日以上。反大发热。再加吐利。即是亡阳。若其人反加
微寒。寒甚于表。上焦应之。必欲呕矣。若加腹痛。是寒甚于里。中焦受之。必欲利矣。当此阴盛。急当扶阳。庶不为
假热所惑而妄治。
但欲寐。即是不得眠。然但欲寐是病情。乃问而知之。不得眠是病形。可望而知之。欲寐是阴虚。不眠是烦躁。故
治法不同。
三阳惟少阳无承气症。三阴惟少阴有承气症。少阳为阳枢。阳稍虚。便入于阴。故不得妄下以虚其元阳。少阴为阴
枢。阳有余。便伤其阴。故当急下以存其真阴。且少阳属木。惟畏其克土。故无下症。少阴主水。更畏有土制。故当急
下。盖真阴不可虚。强阳不可从也。
少阴病。用大承气急下者。有三病症。得病三二日。热淫于内。肾水不支。因转属阳明。胃火上炎。故口燥咽干也。
急下之。谷气下流。津液得生矣。得病六七日。当解不解。津液枯涸。因转属阳明。故腹胀不大便。所谓已入于腑者。
下之则胀已。宜于急下者。六七日来阴虚已极。恐土实于中。心肾不交耳。若自利纯清水。心下痛。口燥舌干者。是土
燥火炎。脾气不濡。胃气反浓。水去而谷不去。故宜于急下。
少阴为性命之枢。少阴病。是死生关。故六经中。独于少阴历言死症。然少阴中风始得时。尚有发热脉沉可证。若
初受伤寒。其机甚微。脉细微。但欲寐。口中和。背恶寒。人已皆不觉其为病也。若身体疼。手足寒。骨节痛。脉浮者。
此表中阳虚症。心中烦。不得卧。此里之阴虚症也。若下利咽痛胸满心烦。与口中气出。唇口燥干。鼻中涕出。蜷卧足
冷。舌上苔滑者。此少阴半表半里。阴阳驳杂之症也。
脉阴阳俱紧。反汗出。而咽痛吐利者。此阴极似阳。肾阳不归。为亡阳症也。若至八九日。一身尽热者。是寒极生
热。肾阳郁极。而胜复太过也。其腹痛下利。小便不利者。有水火之分。若四肢沉重疼痛。为有水气。是阳虚而不胜阴
也。若便脓血。与泄利下重者。此为火。此阳邪陷入阴中也。下利清谷。里寒外热。手足厥逆。脉微欲绝。身反不恶寒。
其人面赤者。是下虚而极阳也。吐利兼作。手足逆冷。烦躁欲死者。是阴极而发躁也。岐伯曰。阴病治阳。阳病治阴。
定其中外。各守其乡。此即仲景治少阴之大法也。
同是恶寒蜷卧。利止手足温者可治。利不止。手足逆冷者不治。时自烦欲去衣被者可治。不烦而躁。四逆而脉不至
者死。同是吐利。手足不逆冷。反发热者不死。烦躁四逆者死。同是呕吐。汗出大便数少者可治。自利烦躁不得卧者死。
盖阴阳互为其根。阴中无阳则死。独阴不生故也。
Shaoyin (Lesser Yin) channel encompasses both Water and Fire qi, with cold and heat syndromes mixed together; therefore, the manifestations are difficult to predict. Its cold-type symptoms resemble Taiyin (Greater Yin) disease, while its heat-type symptoms resemble Taiyang (Greater Yang) disease. Thus, Zhang Zhongjing established the diagnostic criteria based on a pulse that is faint and fine (Wei Xi), and a mental state of drowsiness (Yu Mei), setting principles beyond mere appearances to guide practitioners to seek treatment methods within the specific pathology. By applying this logic to distinguish true from false cold and heat, one can clarify the states of Yin/Yang and Deficiency/Excess. The diagnostic outlines for the other four channels all describe "Excess due to pathogenic Qi flourishing," whereas the Shaoyin outline describes "Deficiency due to Zheng Qi (Upright Qi) depletion," because Shaoyin is the root of the human body. However, pathogenic excess often stems from Zheng deficiency, hence all channels may have indications for warming and tonifying. Conversely, Zheng depletion often results from pathogenic excess, so Shaoyin disease also has indications for sweating, vomiting, and purging therapies. It must be understood that when pathogens are excessive and Zheng is already deficient, securing the root aids in expelling pathogens; when Zheng is not severely deficient but pathogens are excessive, expelling pathogens protects Zheng. This is a major principle.
Shaoyang (Lesser Yang) is the pivot of Yang, and Shaoyin is the pivot of Yin. A Wiry (Xian) pulse corresponds to Wood; Wiry yet fine indicates insufficient Yang. A Faint (Wei) pulse corresponds to Water; Faint yet fine indicates insufficient Yin. These are similarities in pulse quality. Wei Qi (Defensive Qi) moves through Yang during wakefulness and through Yin during sleep. It circulates through Yang twenty-five times, often passing through the divisions of Foot Shaoyin Kidney to reach the Zang-Fu organs. In Shaoyin disease, the pivot mechanism fails, leading to drowsiness. This parallels Shaoyang disease's tendency toward vomiting. Vomiting represents outward movement (Yang/External); sleep represents inward entry (Yin/Internal). "Tendency to vomit" implies an inability to vomit effectively; "drowsiness" implies an inability to stay awake. Both reflect the patient's subjective experience of pivot dysfunction.
In Shaoyin disease, if the pulse is faint, sweating should not be induced, as it would cause Yang collapse. If the pulse is fine, deep, and rapid, the disease is interior, and sweating is contraindicated. However, the potential for sweating exists here. A faint pulse suggests absence of Yang, but a rapid pulse may indicate Yang recovery. One must carefully determine if the disease is interior to forbid sweating, rather than rigidly adhering to the rule that a deep pulse always indicates interior disease precluding sweating. If sweating is performed and the pulse remains deep, the disease is still exterior, and since there are no interior signs, sweating is permissible. If the pulse is floating and slow, indicating exterior heat and interior cold, accompanied by diarrhea with undigested food, the slow pulse indicates absence of Yang and interior disease; one must not sweat simply because the pulse is floating. One must know that Yang resides within Yin, so even a deep pulse may allow sweating; Yin resides within Yang, so even a floating pulse may require warming. If after eight or nine days, the whole body and hands/feet become hot, this indicates Yang moving from interior to exterior, representing Yang excess and Yin deficiency, requiring Yin-nourishing methods. This differs from cases at two or three days without interior signs.
Taiyin is the interior of Yangming. Since Yangming does not fear cold, Taiyin, despite having vomiting, diarrhea, and abdominal pain, lacks aversion to cold. Shaoyin is the interior of Taiyang. Since Taiyang fears cold, Shaoyin vomiting and diarrhea are invariably accompanied by aversion to cold, as Yin follows Yang. In Taiyin, if hands and feet are warm, sudden irritability followed by diarrhea leads to self-healing, utilizing the Yang of the stomach. In Shaoyin vomiting/diarrhea, warmth of hands and feet indicates treatability, while cold extremities indicate untreatability. This shows that lower Jiao deficiency-cold invading the middle Jiao is survivable only if stomach Yang still reaches the limbs, proving that先天 Yuan Yang (Pre-heaven Primordial Yang) relies on 后天 Wei Qi (Post-heaven Stomach Qi) for cultivation.
Taiyang is the Biao (Manifestation) of Shaoyin; Taiyin is the Ben (Root) of Shaoyin. Shaoyin Yin deficiency transfers heat to the Bladder, causing whole-body/hand-foot heat and hematochezia (following Biao). Shaoyin Yang deficiency transfers cold to the Spleen, causing vomiting/diarrhea (following Ben).
Transmission from Shaoyin to Yang channels occurs in two ways: Abdominal distension and constipation after 6-7 days indicates transmission to Yangming (Zang excess transferring to Fu). Whole-body/hand-foot heat after 8-9 days indicates transmission to Taiyang (Yin emerging to Yang, rising from severe diarrhea).
Heat in the Bladder causing blood in stool is Zang-to-Fu transmission, Yin attacking Yang. Qi pathology affecting Blood is Yang attacking Yin. This reflects Shaoyin pivot dynamics. This transition from Yin to Yang shares symptoms with Taiyang Heat Binding in the Bladder but differs in etiology. In Shaoyin disease, a tight pulse lasting 7-8 days with spontaneous diarrhea, sudden faintness of pulse, warming of extremities, and disappearance of tightness, despite irritability and diarrhea, indicates self-healing. This resembles Spleen Fullness in Taiyin. Generally, Shaoyin Yang recovery with a faint pulse shifts to Taiyin, clearing turbidity; strong pulse shifts to Yangming, retaining waste; stagnation leads to interior fullness in Large Intestine; lateral spread affects Taiyang blood regions. Tight-to-faint pulse returns to Shaoyin's original state, resolving via Taiyin. Deep/fine/rapid pulses involve Yang channels, causing illness. Though severe heat is not fatal, it represents a variation of Yin resolving via Yang.
Irritability (Fan) and restlessness (Zao) occur in all six channels but are worse in Shaoyin due to Yin deficiency. Yang excess causes Fan; Yin extreme causes Zao. Fan relates to Qi (internal); Zao relates to Form (external). Zao then Fan means Qi is enslaved by Form. Spontaneous Fan without Zao indicates returning Yang (treatable). Fanless Zao indicates exhaustion of Zang Yang (fatal). Thus, Fan is life, Zao is death in Shaoyin.
Shanghan prioritizes Yang. Yin syndromes with Yang pulses survive; Yin diseases with Yang symptoms are treatable. For curling up, cold limbs, vomiting/diarrhea (Pure Yin/No Yang), reliance on one Yang returning is key. Reverse irritability is treatable; reverse warming of limbs/heat generation is non-fatal.
Both Taiyang and Shaoyin present exterior body/joint pain and interior water retention. Taiyang: Floating/Tight pulse, fever → Ma Huang Tang (stimulate Ying-Wei Yang to harmonize Yin). Shaoyin: Deep pulse, cold limbs → Fu Zi Tang (support Kan Yang to match Yin). Taiyang water is Upper Jiao → Xiao Qing Long Tang (sweat to disperse Yang water). Shaoyin water is Lower Jiao → Zhen Wu Tang (warmth to drain Yin water).
Pulse Yin/Yang both tight resembles Taiyang Shanghan. Tight pulse indicates Cold, fitting Shaoyin. But Yin onset shouldn't sweat; spontaneous sweating indicates Yin extreme mimicking Yang, or Yang deficiency failing to store Essence. Pre-Yang collapse involves Yin loss. Yang unanchored causes sore throat/vomiting; Yin unable to store causes persistent diarrhea. Fu Zi Tang uses Bai Shao/Bai Zhu/Fu Ling to nourish Yin, Ren Shen/Fu Zi to restore Yang, acting as a return-to-root formula.
Kidney governs fluids/sweat. Shaoyin disease prevents fluid ascent, so Yin syndromes shouldn't sweat. Zhang Zhongjing treats Shaoyin exterior with Ma Huang/Xi Xin + Fu Zi to raise Yang/fluids into sweat. If True Yin is forced by heat, water follows fire → spontaneous sweat. Zhang treats Shaoyin interior with Fu Zi Tang + Ren Shen to tonify Kidney fluid and stop sweat.
"Tight pulse Yin/Yang, weak breath" is Shaoyin text collected by Wang Shuhe, causing debate. Shaoyin connects to Lung/Nose → runny nose. Connects to Tongue base → slippery coating. Connects to legs → cold feet. Not called Yang collapse because no sweat/vomit/diarrhea internally. Weak breath, dry lips/nose/runny nose = Internal Heat. Tight pulse, slippery coating, curling/cold feet = Internal Cold. Shaoyin pivot causes cold-heat standoff. Oral/nasal half-exterior/half-interior mirrors Shaoyang's bitter taste, dry throat, vertigo. Do not treat rashly; wait for Day 7 Yang recovery (mild heat, warm limbs). After Day 8, high fever + vomiting/diarrhea = Yang collapse. Mild chills = Exterior cold affecting Upper Jiao (vomiting). Abdominal pain = Interior cold affecting Middle Jiao (diarrhea). In Yin excess, urgently support Yang to avoid being misled by false heat.
"Drowsiness" (Dan Yu Mei) is inability to sleep peacefully. It is a symptom known by inquiry. "Insomnia" (Bu De Mian) is a sign observed visually. Drowsiness indicates Yin deficiency; insomnia indicates irritability. Treatments differ.
Among Three Yang, only Shaoyang lacks Cheng Qi indications. Among Three Yin, only Shaoyin has Cheng Qi indications. Shaoyang is Yang pivot; slight Yang deficiency enters Yin, so do not purge to damage Yuan Yang. Shaoyin is Yin pivot; Yang excess damages Yin, so urgent purging preserves True Yin. Shaoyang (Wood) fears Earth suppression, so no purge. Shaoyin (Water) fears Earth control, so urgent purge is needed. True Yin must not be deficient; Strong Yang must not be followed.
Three indications for Da Cheng Qi Tang in Shaoyin:
1. Days 2-3: Heat rampant inside, Kidney Water failing, transferring to Yangming, Stomach Fire flaring → dry mouth/throat. Urgent purge allows grain Qi to flow down, generating fluids.
2. Days 6-7: Failure to resolve, fluids dried, transferring to Yangming → abdominal distension/constipation. Disease entered Fu, purge resolves distension. Urgent purge needed due to extreme Yin deficiency and risk of Heart-Kidney non-interaction.
3. Clear watery diarrhea, epigastric pain, dry mouth/tongue: Dry Earth/Fire flare, Spleen not moistening, Stomach thick/concentrated. Water gone, grain remains. Urgent purge required.
Shaoyin is the pivot of life/death. Only Shaoyin details fatal cases. Early Shaoyin Wind Strike has fever/deep pulse. Initial Shanghan is subtle: fine/faint pulse, drowsiness, neutral mouth, back aversion to cold, unnoticed. Body pain/cold limbs/joint pain/floating pulse = Exterior Yang deficiency. Irritability/insomnia = Interior Yin deficiency. Diarrhea/sore throat/chest fullness/irritability + weak breath/dry lips/runny nose/curling/cold feet/slipping coating = Shaoyin Half-Exterior/Half-Interior, mixed Yin/Yang.
Tight pulse Yin/Yang + sweat + sore throat/vomit/diarrhea = Yin extreme mimicking Yang, Kidney Yang departing, Yang collapse. Days 8-9 whole body heat = Cold extreme generating heat, Kidney Yang stagnant/rebounding excessively. Abdominal pain/diarrhea/urinary difficulty = Water/Fire distinction. Heavy/painful limbs = Water Qi (Yang deficiency cannot overcome Yin). Pus/blood in stool/heavy feeling = Fire (Yang pathogen sinking into Yin). Undigested diarrhea/interior cold/exterior heat/cold limbs/faint pulse/no aversion to cold/red face = Lower deficiency/Extreme Yang. Vomit/diarrhea/cold limbs/severe irritability = Yin extreme causing agitation. Qibo said: Treat Yang for Yin disease, Yin for Yang disease, stabilize center/periphery. This is Zhang Zhongjing's major Shaoyin method.
Same aversion to cold/curling: Diarrhea stops/warm limbs = Treatable. Diarrhea continues/cold limbs = Untreatable. Spontaneous irritability/removing clothes = Treatable. No irritability/restlessness/cold limbs/no pulse = Fatal. Same vomit/diarrhea: Limbs not cold/reverse heat = Non-fatal. Irritability/cold limbs = Fatal. Same vomiting: Sweat/frequent small stools = Treatable. Self-diarrhea/irritability/insomnia = Fatal. Yin/Yang are roots of each other; Yin without Yang dies; Pure Yin cannot generate life.