【纲】仲景曰。太阳病。下之。其脉促。不结胸者。此为欲解也。脉浮者。必结胸也。脉紧者。
必咽痛。脉弦者。必两胁拘急。脉细数者。头痛未止。脉沉紧者。必欲呕。脉沉滑者。协热利。
脉浮滑者。必下血。
【目】魏荔彤曰。此条兼言太阳中风伤寒。邪仍在表。误下而变症不一也。脉促而不结胸。阳气
犹充。不为阴药所结。旋欲透表而愈。故为欲解。此下之无害者。幸也。外此则脉浮。病虽在表。
而风邪已为阴药引之入胸。与阳相结。故成结胸也。若脉虽浮而紧。此寒伤荣而误下也。故寒邪与肝
热相激而咽痛。结胸者不咽痛。陷胸之症也。咽痛者不结胸。非少阴甘草桔梗汤之症。仍太阳麻杏
甘石汤之症也。此犹下后之易审治者也。至脉弦者。阴药引寒邪入胁而拘急。然非少阳柴胡之症。
惟宜于太阳胁下满诸条内比类求治。脉细数似少阴。然头痛不止。症仍太阳。乃下后之阳伏郁而为
细数。仍应于太阳误下诸条内。求表里兼治之法。然此数者。其脉俱仍带浮。犹易认也。更有脉沉
紧。全非太阳矣。然误下后之沉紧。阳为阴郁。逆而上冲作呕。则仍应从太阳诸条内。求表里兼治
之法。更有沉滑而协热利。应于太阳下利诸条求治。此二者。不可因脉沉而不浮。遽谓非太阳也。
至脉或浮滑。为表为里。又难认矣。然于必下血。知其为太阳犯本。惟应于太阳犯本下血诸条求治
也。总之。误下变症多端。要人细为审谛。总不容舍太阳别求。一误再误。促人命期。
【纲】仲景曰。太阳病不解。热结膀胱。其人如狂。血自下。下者愈。其外不解者。尚未可攻。
当先解外。外解已。但少腹急结者。乃可攻之。宜桃仁承气汤。
【目】鳌按。此小便尿血也。缘阳气太重。标本俱病。血得热则行。故尿血。若热极则血反结。
少腹为膀胱之室。故膀胱之热结。少腹必急结。用桃仁承气以攻其里之结血。所以解之也。
【纲】仲景曰。淋家不可发汗。发汗必便血。
【目】魏荔彤曰。膀胱气化。何以有血。以素日膀胱腑中。原有蓄热。以伤寒水之化元。再发
太阳经汗。标伤连属于本。水不足而血妄溢。此血与伤风犯本之圊血。相类而实不同。彼为标表不
解所郁。犯及本府阴分。此为标表汗出所累。伤及本经阳分。阴分之血。属在下焦血海所注。故从
大便出。阳分之水。化气不充。血热溢入。故从小便出。
鳌按。此条便血。亦是小便尿血也。盖淋家之膀胱。本为热所素闭。又发其汗。故膀胱愈扰。
血从小便出也。凡论中所言下血。有大便小便之不同。学人审之。
【纲】仲景曰。太阳病。以火熏之。不得汗。其人必躁。过经不解。必圊血。名为火邪。
【目】柯琴曰。他条以火发汗而衄血。是阳邪盛于阳位。故在未过经时。此条以火熏不得汗而
圊血。是阳邪下陷入阴分。故在过经不解时。
【纲】仲景曰。病患无表里症。发热。七八日不大便。虽脉浮数者。可下之。假令已下。脉数
不解。合热则消谷善饥。至六七日不大便者。有瘀血也。宜抵当汤。若脉数不解。而下利不止。必
协热而便脓血也。
【目】柯琴曰。合热协热。内外热也。内外热极。阳盛阴虚。必伤阴络。故不大便者。必有蓄
血。热利不止。必大便脓血。宜黄连阿胶汤。
【纲】张仲景说：太阳病，经过泻下治疗后，脉象急促，没有形成结胸证的，这是病情将要解除的表现。如果脉象浮，一定会形成结胸证。脉象紧的，一定会出现咽痛。脉象弦的，一定会出现两侧胁肋部拘急不舒。脉象细数的，头痛不会停止。脉象沉紧的，一定想要呕吐。脉象沉滑的，会出现协热利（伴随发热的腹泻）。脉象浮滑的，一定会出现便血。
【目】魏荔彤说：这一条同时论述了太阳中风和伤寒，邪气仍在体表，误用泻下法导致变证不一。脉象急促而没有结胸，说明阳气仍然充盛，没有被阴寒药物所郁结，随即能够透达体表而痊愈，所以说是将要解除。这是误下后没有造成危害的情况，算是侥幸。除此之外，如果脉象浮，虽然病在体表，但风邪已经被阴寒药物引入胸中，与阳气相结，所以形成结胸证。如果脉象虽然浮而且紧，这是寒邪伤及营分而误用泻下法，所以寒邪与肝热相互激荡而出现咽痛。结胸证不会出现咽痛，那是陷胸汤证；出现咽痛的不会形成结胸，这不是少阴病的甘草桔梗汤证，仍然是太阳病的麻杏甘石汤证。这还是误下后容易诊断和治疗的情况。至于脉象弦的，是阴寒药物引导寒邪进入胁部而导致拘急，但这不是少阳病的柴胡汤证，只应当在太阳病胁下满的各条文中类比寻求治疗方法。脉象细数似乎像少阴病，但是头痛不止，症状仍然属于太阳病，这是误下后阳气伏郁而表现为细数脉，仍然应当在太阳病误下的各条文中，寻求表里兼治的方法。然而这几种情况，其脉象都仍然带有浮象，还比较容易辨认。更有脉象沉紧的，完全不像太阳病了。但是误下后的沉紧脉，是阳气被阴寒郁遏，逆而上冲引起呕吐，那么仍然应当从太阳病的各条文中，寻求表里兼治的方法。更有脉象沉滑而伴有协热利的，应当在太阳病下利的各条文中寻求治疗。这两种情况，不能因为脉象沉而不浮，就匆忙断定不是太阳病。至于脉象或浮滑，分辨是表证还是里证，又难以辨认了。但是从一定会便血这一点，知道这是太阳病侵犯本经（膀胱），只应当在太阳病犯本经导致便血的各条文中寻求治疗。总之，误用泻下法导致的变证多种多样，关键在于让人仔细审察，总不应该舍弃太阳病去别处求治，一误再误，会加速病人的死亡。
【纲】张仲景说：太阳病没有解除，热邪结聚在膀胱部位，病人神志如狂，血液自行下行，如果能自行下行，病就会好。如果体表的病症还没有解除，还不可以攻逐里实，应当先解表。表证解除后，如果只是小腹部急迫结滞，才可以攻逐里实，适宜使用桃仁承气汤。
【目】沈金鳌按语：这是小便尿血的情况。因为阳气太盛，标本都受病，血遇到热就会运行妄行，所以出现尿血。如果热极，血液反而凝结。小腹是膀胱所在的部位，所以膀胱的热邪结聚，小腹必然急迫结滞。使用桃仁承气汤来攻逐体内的结血，以此来化解它。
【纲】张仲景说：淋家（患有淋病的人）不可发汗，发汗一定会导致便血。
【目】魏荔彤说：膀胱的气化功能，为什么会有血？因为平时膀胱腑中原本就有蓄积的热邪，再加上伤寒水液代谢元气的变化，再次发太阳经的汗，标（表）受伤连属于本（里），津液不足而血液妄溢。这种血与伤风侵犯本经导致的便血，相似而实际上不同。那种情况是因为表邪未解所郁闭，侵犯到本府的阴分；这种情况是因为表证发汗所累及，伤及本经的阳分。阴分的血，属于在下焦血海注入的，所以从大便排出；阳分的水，气化不充足，血热溢出，所以从小便排出。
沈金鳌按语：这一条所说的便血，也是指小便尿血。大概淋家的膀胱，本来就被热邪长期闭塞，又发其汗，所以膀胱更加受扰，血液从小便排出。凡是医论中所说的下血，有大便和小便的不同，学习的人要仔细审察。
【纲】张仲景说：太阳病，用火熏法治疗，没有出汗，病人一定烦躁。过了经界时间仍未解除，一定会便血，这称为火邪。
【目】柯琴说：其他条文用火发汗导致衄血（鼻出血），是阳邪盛于阳位，所以在未过经的时候发生。这一条用火熏法没有出汗而便血，是阳邪下陷入阴分，所以在过经未解的时候发生。
【纲】张仲景说：病人没有表证也没有里证，发热，七八天不大便，虽然脉象浮数，可以用泻下法。假如已经用了泻下法，脉数不解，合热则消谷善饥（吃得多饿得快），到了六七天又不大便的，是有瘀血，适宜使用抵当汤。如果脉数不解，而下利不止，一定是协热而便脓血。
【目】柯琴说：合热、协热，是指内热和外热。内外热极，阳盛阴虚，必然会损伤阴络，所以不大便的，一定有蓄血；热利不止，必定是大便脓血，适宜使用黄连阿胶汤。
[General Principle] Zhang Zhongjing said: In Taiyang disease, after purgation, if the pulse is rapid (Cu) and there is no Jie Xiong (Chest Binding), this indicates that the condition is about to resolve. If the pulse is floating (Fu), Jie Xiong will definitely occur. If the pulse is tight (Jin), throat pain will definitely occur. If the pulse is wiry (Xian), bilateral hypochondriac stiffness and urgency will definitely occur. If the pulse is fine and rapid (Xi Shu), the headache will not cease. If the pulse is deep and tight (Chen Jin), vomiting will definitely be desired. If the pulse is deep and slippery (Chen Hua), Xie Re Li (Diarrhea with Heat) will occur. If the pulse is floating and slippery (Fu Hua), lower bleeding (Xia Xue) will definitely occur.
[Detailed Commentary] Wei Litong stated: This clause discusses both Wind Strike and Cold Damage of the Taiyang stage, where the pathogen remains in the exterior. Mistaken use of purgation leads to various transformed syndromes. A rapid pulse without Jie Xiong indicates that Yang Qi is still abundant and not constrained by Yin-cold herbs; it soon penetrates the exterior to heal, hence described as "about to resolve." This is a fortunate case where purgation caused no harm. Otherwise, if the pulse is floating, although the disease is in the exterior, the Wind pathogen has been drawn into the chest by Yin-cold herbs and binds with Yang, forming Jie Xiong. If the pulse is floating yet tight, this is Cold damaging the Ying (Nutrient) level followed by mistaken purgation; thus, Cold pathogen agitates with Liver Heat, causing throat pain. Jie Xiong does not involve throat pain; it is a syndrome for Xia Xiong Tang (Drain the Chest Decoction). Throat pain without Jie Xiong is not a syndrome for Gan Cao Jie Geng Tang (Licorice and Platycodon Decoction of Shaoyin), but rather remains a syndrome for Ma Xing Shi Gan Tang (Ephedra, Apricot Kernel, Gypsum, and Licorice Decoction of Taiyang). This is still relatively easy to diagnose and treat after purgation. Regarding a wiry pulse, Yin-cold herbs draw Cold pathogen into the hypochondrium causing stiffness, but this is not a Chai Hu Tang (Bupleurum Decoction) syndrome of Shaoyang; one should seek treatment by analogy within the Taiyang clauses concerning fullness below the ribs. A fine and rapid pulse resembles Shaoyin, but since the headache persists, the syndrome remains Taiyang; this is Yang Qi constrained and depressed after purgation manifesting as a fine and rapid pulse. One should still seek combined exterior-interior treatment methods within the Taiyang mistaken-purgation clauses. However, in these cases, the pulses all retain a floating quality, making them relatively easy to recognize. Furthermore, a deep and tight pulse appears completely unlike Taiyang. Yet, the deep and tight pulse after mistaken purgation indicates Yang Qi depressed by Yin, counter-flowing upward to cause vomiting; thus, one should still seek combined exterior-interior treatment within the Taiyang clauses. A deep and slippery pulse with Xie Re Li should be treated according to the Taiyang diarrhea clauses. These two conditions should not be hastily dismissed as non-Taiyang simply because the pulse is deep and not floating. As for a floating or slippery pulse, distinguishing between exterior and interior is difficult. However, knowing that lower bleeding will occur indicates the Taiyang stage has affected its root organ (Bladder); treatment should be sought within the Taiyang root-organ lower bleeding clauses. In summary, mistaken purgation causes myriad transformed syndromes; the key lies in careful examination. One must never abandon the Taiyang framework to seek treatment elsewhere; repeated errors will hasten death.
[General Principle] Zhang Zhongjing said: When Taiyang disease is unresolved, Heat accumulates in the Bladder region. The patient exhibits a manic-like state (Ru Kuang). If blood flows out spontaneously, the patient heals. If the exterior symptoms are not yet resolved, internal attack is contraindicated; one must first release the exterior. Once the exterior is resolved, if only the lower abdomen feels urgent and knotted (Ji Jie), then internal attack may proceed, using Tao Ren Cheng Qi Tang (Peach Kernel and Magnolia Bark Decoction).
[Detailed Commentary] Shen Jin'ao noted: This refers to hematuria (blood in urine). It arises because Yang Qi is excessive, affecting both the root and branch. Blood moves freely when heated, hence hematuria occurs. If heat becomes extreme, blood coagulates instead. The lower abdomen is the chamber of the Bladder; thus, Bladder Heat accumulation causes lower abdominal urgency and knotting. Tao Ren Cheng Qi Tang is used to purge the internal blood stasis, thereby resolving the condition.
[General Principle] Zhang Zhongjing said: Patients with Lin Syndrome (Dysuria) must not undergo sweating therapy; inducing sweat will inevitably lead to lower bleeding.
[Detailed Commentary] Wei Litong stated: Why is there blood in Bladder Qi transformation? Because there is pre-existing accumulated Heat in the Bladder Fu organ. Combined with the metabolic changes of Cold Damage water, inducing sweat from the Taiyang channel injures the branch (exterior) which connects to the root (interior). Fluid deficiency leads to reckless blood overflow. This bleeding is similar to, yet distinct from, rectal bleeding caused by Wind Strike affecting the root organ. The latter results from exterior pathogens remaining unresolved, invading the Yin aspect of the root Fu. This case results from sweating depleting the exterior, injuring the Yang aspect of the root channel. Blood of the Yin aspect belongs to the Lower Jiao Blood Sea and exits via the large intestine (feces). Water of the Yang aspect fails to transform Qi adequately; Blood Heat overflows and exits via the small intestine (urine).
Shen Jin'ao noted: This clause's "lower bleeding" also refers to hematuria. The Bladder of a Lin patient is chronically closed by Heat; inducing sweat further disturbs the Bladder, causing blood to exit via urine. In medical texts, "lower bleeding" differs between fecal and urinary sources; students must examine this carefully.
[General Principle] Zhang Zhongjing said: In Taiyang disease, if Fire Moxibustion/Fumigation is applied and sweat does not ensue, the patient will become irritable. If the disease passes the meridian cycle without resolving, lower bleeding will definitely occur; this is termed Huo Xie (Fire Pathogen).
[Detailed Commentary] Ke Qin stated: In other clauses, fire-induced sweating leads to epistaxis (nosebleed) because Yang pathogen is abundant in Yang positions, occurring before the meridian cycle passes. In this clause, fire fumigation without sweating leads to lower bleeding because Yang pathogen sinks into the Yin aspect, occurring when the meridian cycle has passed and remains unresolved.
[General Principle] Zhang Zhongjing said: If a patient presents with neither exterior nor interior symptoms, fever, and constipation for seven to eight days, even if the pulse is floating and rapid, purgation may be used. If purgation has already been administered and the rapid pulse persists, combined Heat causes excessive hunger and digestion. If, after six or seven days, constipation recurs, this indicates Blood Stasis; Dang Dang Tang (Tussuck Pill) is indicated. If the rapid pulse persists and diarrhea continues incessantly, this is Xie Re Bian Nong Xue (Heat-associated pus and blood in stool).
[Detailed Commentary] Ke Qin stated: "Combined Heat" and "Xie Re" refer to internal and external Heat. Extreme internal and external Heat, characterized by Yang excess and Yin deficiency, damages the Yin collaterals. Thus, constipation indicates Blood Accumulation (Xu Xue); continuous hot diarrhea indicates pus and blood in stool. Huang Lian E Jiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is indicated.