太阳病六七日，表症仍在，而反下之，脉微而沉，反不结胸，其人发狂者，以热在下焦，少腹当硬满，小便
自利者，下血乃愈。所以然者，以太阳随经瘀热在里故也，抵当汤主之。
此亦病发于阳误下热入之症也。表症仍在下，当有而反下之句。太阳病六七日不解，脉反沉微，宜四逆汤救
之。此因误下，热邪随经入府，结于膀胱，故少腹硬满而不结胸，小便自利而不发黄也。太阳经少气多血，病六
七日而表症仍在，阳气重可知。阳极则扰阴，故血燥而蓄于中耳。血病则知觉昏昧，故发狂。此经病传府，表病
传里，气病传血，上焦病而传下焦也。少腹居下焦，为膀胱之室，厥阴经脉所聚，冲任血海所由，瘀血留结，故
硬满。然下其血而气自舒，攻其里而表自解矣。《难经》云∶“气结而不行者，为气先病；血滞而不濡者，为血
后病。”深合此症之义。
太阳病身黄，脉沉结，少腹硬，小便不利者，为无血也。小便自利，其人如狂者，血结症也，抵当汤主之。
太阳病发黄与狂，有气血之分。小便不利而发黄者，病在气分，麻黄连翘赤小豆汤症也。若小便自利而发狂
者，病在血分，抵当汤症
也。湿热留于皮肤而发黄，卫气不行之故也。燥血结于膀胱而发黄，营气不敷之故也。沉为在里，凡下后热入
之症，如结胸、发黄、蓄血，其脉必沉。或紧、或微、或结，在乎受病之轻重，而不可以因症分也。水结、血结，
俱是膀胱病，故皆少腹硬满。小便不利是水结，小便自利是血结。如字，助语辞。若以如字实讲，与蓄血发狂
分轻重，则谬矣。
伤寒有热，少腹满，应小便不利。今反利者，为有血也，当下之，不可余药，宜抵当丸。
有热即表症仍在。少腹满而未硬，其人未发狂。只以小便自利，预知其为有蓄血，故小其制而丸以缓之。
抵当汤∶
水蛭（熬） 虻虫（去翅足熬各三十个） 桃仁（二十粒）活大黄（三两，酒洗）
上四味，以水五升，煮取三升，去滓，温服一升。不下再服。
抵当丸∶
水蛭（三十个） 虻虫（二十五个） 桃仁（二十个） 大黄（三两）
上四味。杵分为四丸，以水二升，煮一丸，取七合服之， 时当下血。若不下者更服。
蛭，昆虫之饮血者也，而利于水。虻，飞虫之吮血者也，而利于陆。以水陆之善取血者，用以攻膀胱蓄血，
使出乎前阴。佐桃仁之苦甘而推陈致新，大黄之苦寒而荡涤邪热。名之曰抵当者，直抵其当攻之处也。
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。
阳气太重，标本俱病，故其人如狂。血得热则行，故尿血也。血下则不结，故愈。冲任之血，会于少腹。
热极则血不下而反结，故急。然病自外来者，当先审表热之轻重以治其表，继用桃仁承气以攻其里之结血。此少
腹未硬满，故不用抵当。然服五合取微利，亦先不欲
下意。
首条以反不结胸句，知其为下后症。此以尚未可攻句，知其为未下症。急结者宜解，只须承气；硬满者不易
解，必仗抵当。表症仍在，竟用抵当，全罔顾表者，因邪甚于里，急当救里也。外症已解，桃仁承气未忘桂枝
者，因邪甚于表，仍当顾表也。
桃仁承气汤∶
桃仁（五十个） 甘草 桂枝 芒硝（各二两） 大黄（四两）
上五味，以水七升，煮取二升半，去滓，内芒硝，更上火微沸。下火先食温服五合，日三服，当微利。
阳明病，其人喜忘者，必有蓄血。所以然者，本有久瘀血，故令喜忘。屎虽硬，大便反易，其色必黑，宜
抵当汤下之。
瘀血是病根，喜忘是病情。此阳明未病前症，前此不知，今因阳明病而究其由也。屎硬为阳明病，硬则大
盒饭难而反易，此病机之变易见矣。原其故必有宿血，以血主濡也。血久则黑，火极反见水化也。此以大便反易
之机，因究其色之黑，乃得其病之根，因知前此喜忘之病情耳。承气本阳明药。不用桃仁承气者，以大便易，
不须芒硝；无表症，不得用桂枝；瘀血久，无庸甘草。非虻虫、水蛭，不胜其任也。
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。
不头痛恶寒，为无表症，不烦燥呕渴，为无里症，非无热也。七八日下，当有不大便句。故脉虽浮数，有可
下之理，观下后六七日犹然不便可知。合热协热，内外热也。前条据症推原，此条凭脉辨症。表里热极，阳盛
阴虚，必伤阴络。故仍不大便者，必有蓄血，热利不止，必大便脓血矣。宜黄连阿胶汤主之。上条大便反易，
知瘀血留久，是验之于已形。此条仍不大便，知瘀血已结，是料之于未形。六经惟太阳、阳明有蓄血症，以二经
多血故也，故脉症异而治则同。
太阳协热利，有虚有热。阳明则热而不虚。少阴便脓血属于虚，阳明则热。数为虚热，不能消谷。消谷善
饥，此为实热矣。
太阳病经过六七天，表证仍然存在，反而使用了攻下法，脉象微而沉，却没有形成结胸证，病人出现发狂的症状，这是因为热邪在下焦，小腹部应当硬满，小便通畅自如的，通过泻下瘀血才能痊愈。之所以这样，是因为太阳经的邪热随经入里，瘀热蕴结在体内，应当用抵当汤主治。
这也是病发于阳经，误用下法导致热邪内陷的病症。“表证仍在”与“反下之”这两句之间，省略了“当有……”的意思。太阳病六七天未解，脉象反而沉微，本应用四逆汤来救治。这里是因为误用下法，热邪顺着经络进入腑脏，结聚在膀胱，所以小腹部硬满而不形成结胸，小便通畅而不发黄。太阳经气少血多，患病六七天而表证仍在，可知阳气亢盛到了极点。阳极则扰动阴分，导致血液燥热而蓄积在中焦。血分有病则知觉昏乱，所以发狂。这是经病传入腑，表病传入里，气病传入血分，上焦病传入下焦。小腹部位于下焦，是膀胱所在的部位，也是厥阴经脉汇聚之处，冲脉和任脉（血海）由此而出，瘀血留滞结聚，所以硬满。然而，攻下瘀血后气机自然舒畅，攻逐里实而表证自然解除。《难经》说：“气结聚而不能运行，是气先生病；血液停滞而不能濡养，是血后生病。”这深深契合此病症的道理。
太阳病身体发黄，脉象沉涩，小腹部硬，小便不利的，属于无瘀血（水湿内停）。小便通畅，病人像发狂一样的，是血结证，用抵当汤主治。
太阳病发黄与发狂，有气分和血分的区别。小便不利而发黄的，病在气分，是麻黄连翘赤小豆汤证。如果小便通畅而发狂的，病在血分，是抵当汤证。湿热滞留于皮肤而发黄，是卫气不能运行的缘故。燥热之血结聚在膀胱而发黄，是营气不能敷布的缘故。沉脉主病在里，凡是攻下后热邪内陷的病症，如结胸、发黄、蓄血，其脉象必定沉。或者紧、或者微、或者涩，取决于受病的轻重，而不能因为症状不同就改变判断。水结和血结，都是膀胱的病，所以都表现为小腹部硬满。小便不利是水结，小便通畅是血结。“如”字，是语气助词。如果把“如”字当作实义来讲，用来区分蓄血发狂的轻重，那就错了。
伤寒发热，小腹胀满，应该小便不利。现在反而小便通畅，是有瘀血，应当攻下，不可用其他药物，宜用抵当丸。
“有热”即表示表证仍在。小腹胀满但未硬，病人没有发狂。仅凭小便通畅，预先知道是有蓄血，所以减小药量制成丸剂以缓和药力。
抵当汤方：
水蛭（熬制） 虻虫（去掉翅膀和足，熬制，各三十个） 桃仁（二十粒） 生大黄（三两，酒洗）
以上四味药，用水五升，煮取三升，去渣，温服一升。若不下血，再服。
抵当丸方：
水蛭（三十个） 虻虫（二十五个） 桃仁（二十个） 大黄（三两）
以上四味药，捣碎分成四丸，用水二升，煮一丸，取七合服用，到时候应该会下血。如果不下血，再服。
水蛭，是昆虫中吸食血液的，善于在水中取血。虻，是飞虫中吮吸血液的，善于在陆地上取血。用水陆两栖善于取血的虫类，用来攻逐膀胱中的蓄血，使瘀血从前阴排出。佐以桃仁的苦甘之性来推陈出新，佐以大黄的苦寒之性来荡涤邪热。命名为“抵当”，意思是直抵应当攻伐的部位。
太阳病不解，热邪结聚在膀胱，病人像发狂一样，如果瘀血能自行排出，排出的就会痊愈。如果表证仍未解除，还不可以攻下，应当先解表。表证解除后，只是小腹部急迫结聚的，才可以攻下，宜用桃仁承气汤。
阳气太盛，标本俱病，所以病人像发狂。血得热则流动，所以会出现尿血。血下行则不结聚，所以痊愈。冲脉和任脉的血，汇聚于小腹部。热极则血不但不行反而结聚，所以感到急迫。然而病从外来的，应当先审察表热的轻重来治疗表证，继之用桃仁承气汤来攻逐里的结血。这里小腹部未硬满，所以不用抵当汤。然而服用五合（约半升）以求轻微通利，也是起初不想急于攻下的意思。
第一条通过“反不结胸”一句，知道这是误下后的病症。这一条通过“尚未可攻”一句，知道这是未误下的病症。急结者适宜解表兼活血，只需承气汤类；硬满者不易解，必须依靠抵当汤。表证仍在，竟用抵当汤，完全不顾表证，是因为邪气重于里，急需救里。外证已解，桃仁承气汤不忘用桂枝，是因为邪气重于表，仍应当顾护表证。
桃仁承气汤方：
桃仁（五十个） 甘草 桂枝 芒硝（各二两） 大黄（四两）
以上五味药，用水七升，煮取二升半，去渣，加入芒硝，再次上火微沸。去火，饭前温服五合，每日三次，应当轻微通利。
阳明病，病人喜欢遗忘的，必有蓄血。之所以这样，是因为原本就有久瘀血，所以导致喜欢遗忘。大便虽然硬，排便反而容易，颜色必定黑，宜用抵当汤攻下。
瘀血是病根，喜忘是病情表现。这是阳明病发生前的症状，此前不知，现在因患阳明病而追究其原因。大便硬是阳明病，硬则大便应当难解却反而容易，这是病机的变化可见一斑。推究其原因，必有宿血，因为血主濡润。血久则变黑，火极反见水化之象。这是通过大便反而容易的现象，进而追究颜色的黑，才找到病的根源，从而知道此前喜忘的病情。承气汤本是治疗阳明病的药。不用桃仁承气汤，是因为大便易解，不需要芒硝；没有表证，不能用桂枝；瘀血日久，不需要甘草。若非虻虫、水蛭，不能胜任攻逐瘀血的任务。
病人没有表证和里证，发热，七八天不大便，虽然脉象浮数，可以攻下。假如已经攻下，脉数不解，合热则消谷善饥，到了六七天又不大便的，是有瘀血，宜用抵当汤。如果脉数不解，而下利不止，必定协热而便脓血。
不头痛恶寒，为无表证，不烦躁呕渴，为无里证，并非没有热。七八天下来，应当有不大便的情况。所以脉虽浮数，有可下的道理，看攻下后六七天仍然不便可知。合热与协热，指内外之热。前一条根据症状推究原因，这一条凭脉象辨别症状。表里热极，阳盛阴虚，必伤阴络。所以仍然不大便的，必有蓄血；热利不止，必定大便脓血。宜用黄连阿胶汤主治。上一条大便反易，知道瘀血停留已久，这是在已形成的症状上验证。这一条仍然不大便，知道瘀血已经结聚，这是在未形成的症状上推测。六经中只有太阳、阳明有蓄血症，因为这两经多血，所以脉症不同但治则相同。
Taiyang disease (Disease of the Taiyang/Bladder channel) for six or seven days, with exterior symptoms still present, but mistakenly treated with purgation. The pulse is faint and deep. There is no formation of Jie Xiong (Chest Binding), yet the patient becomes manic. This is due to heat in the Lower Jiao (Lower Burner). The lower abdomen should be hard and full. If urination is normal, recovery comes only after evacuating blood. The reason for this is that heat from the Taiyang channel has followed the meridians into the interior, where stasis-heat resides. Di Dang Tang (Resist the Decoction) is the primary treatment.
This is also a case of illness originating in Yang, where mistaken purgation caused heat to enter inward. The phrase "exterior symptoms still present" implies a contrast with "mistakenly treated with purgation." In Taiyang disease lasting six or seven days without resolution, if the pulse becomes faint and deep, Si Ni Tang (Frigid Extremities Decoction) should ideally be used to rescue the condition. Here, due to mistaken purgation, pathogenic heat follows the meridians into the Fu organs, knotting in the Bladder. Thus, the lower abdomen is hard and full without forming Jie Xiong, and urination is free without jaundice. The Taiyang channel has little Qi and much Blood. After six or seven days, with exterior symptoms still present, it can be known that Yang Qi is heavy. Extreme Yang disturbs Yin, causing Blood to become dry and accumulate in the middle. When Blood is diseased, perception becomes confused, leading to mania. This represents the transmission of Jing (Channel) disease to Fu (Organ), exterior disease to interior, Qi disease to Blood, and Upper Jiao disease to Lower Jiao. The lower abdomen resides in the Lower Jiao and is the chamber of the Bladder, the gathering place of the Jueyin channel, and the source of the Chong and Ren vessels (Sea of Blood). Stasis-blood remains and knots, causing hardness and fullness. However, by attacking the Blood, Qi naturally relaxes; by attacking the interior, the exterior naturally resolves. The Nan Jing states: "When Qi knots and cannot move, it is Qi that is sick first; when Blood stagnates and cannot nourish, it is Blood that is sick later." This deeply fits the meaning of this syndrome.
In Taiyang disease, if there is yellowing of the body, a deep and knotted pulse, and a hard lower abdomen, but urination is difficult, this indicates no Blood stasis (it is water retention). If urination is free and the patient appears manic, this is a Blood Knot syndrome, treated with Di Dang Tang.
There is a distinction between Qi and Blood in Taiyang disease presenting with jaundice versus mania. Jaundice with difficult urination belongs to the Qi level and is a Ma Huang Lian Qiao Chi Xiao Dou Tang (Ephedra, Forsythia, and Small Soybean Decoction) syndrome. If urination is free and mania occurs, it belongs to the Blood level and is a Di Dang Tang syndrome. Damp-heat lingering in the skin causes jaundice due to the failure of Wei Qi (Defensive Qi) to circulate. Dry-blood knotting in the Bladder causes jaundice due to the failure of Ying Qi (Nutritive Qi) to distribute. A deep pulse indicates disease in the interior. For any condition where heat enters inward after purgation, such as Jie Xiong, jaundice, or Blood Accumulation, the pulse must be deep. It may be tight, faint, or knotted, depending on the severity of the pathogen, and should not be differentiated solely by symptoms. Both Water Knot and Blood Knot are diseases of the Bladder, hence both present with a hard and full lower abdomen. Difficult urination indicates Water Knot; free urination indicates Blood Knot. The character "Ru" (like/as if) here is an interjection. Interpreting it literally to distinguish the severity of Blood Accumulation and mania would be erroneous.
In Shang Han (Cold Damage) with fever and a full lower abdomen, urination should be difficult. Now that it is free, there is Blood stasis. It should be purged. Do not use other medicines; Di Dang Wan (Resist the Pill) is suitable.
"Having heat" means exterior symptoms are still present. The lower abdomen is full but not hard, and the patient has not become manic. Relying only on free urination, one anticipates Blood Accumulation. Therefore, the dosage is reduced and made into pills to act gently.
Di Dang Tang Formula:
Shui Zhi (Leech, processed) - amount unspecified in text snippet but implied equal parts contextually or standard dosage; here listed as ingredient.
Meng Chong (Dragonfly larva, wings and feet removed, processed) - 30 units.
Tao Ren (Peach Kernel) - 20 units.
Huang Di Huang (Raw Rhubarb Root, washed with wine) - 3 liang.
These four ingredients are boiled in 5 sheng of water to obtain 3 sheng. Strain and take 1 sheng warm. If stool does not pass, take again.
Di Dang Wan Formula:
Shui Zhi (Leech) - 30 units.
Meng Chong (Dragonfly larva) - 25 units.
Tao Ren (Peach Kernel) - 20 units.
Da Huang (Rhubarb Root) - 3 liang.
These four ingredients are pounded and divided into four pills. Boil one pill in 2 sheng of water to obtain 7 he of liquid. Take this dose. Stool containing blood should pass at this time. If it does not pass, take another dose.
The leech is an insect that drinks blood and excels in water. The dragonfly larva sucks blood and excels on land. Using these creatures, skilled at taking blood from water and land, to attack Bladder Blood Accumulation allows the blood to exit via the anterior yin. Peach Kernel assists with its bitter-sweet nature to push out the old and generate the new. Rhubarb assists with its bitter-cold nature to sweep away pathogenic heat. It is named "Di Dang" (Resist the/Directly Hit the), meaning to strike directly at the site requiring attack.
If Taiyang disease does not resolve, and heat knots in the Bladder, the patient appears manic. If Blood discharges spontaneously, discharge leads to recovery. If exterior symptoms remain unresolved, attack is not yet appropriate; one should first release the exterior. Once the exterior is resolved, if only the lower abdomen feels urgent and knotted, then attack is possible. Tao Ren Cheng Qi Tang (Peach Kernel and Minor Order the Qi Decoction) is suitable.
Yang Qi is excessively heavy, affecting both root and branch, so the patient appears manic. Blood moves when heated, so hematuria occurs. When Blood descends, it does not knot, so recovery ensues. The blood of the Chong and Ren vessels gathers in the lower abdomen. Extreme heat causes Blood not to flow but to knot, resulting in urgency. However, since the pathogen comes from outside, one must first examine the severity of exterior heat to treat the exterior, then use Tao Ren Cheng Qi Tang to attack the interior Blood knot. Since the lower abdomen is not yet hard and full, Di Dang Tang is not used. Taking five he (approx. half a sheng) aims for mild purgation, indicating an initial reluctance to purge aggressively.
The first clause uses "but no Jie Xiong" to identify this as a post-purgation syndrome. This clause uses "attack is not yet appropriate" to identify this as a pre-purgation syndrome. Urgent knotting requires release; Minor Order the Qi suffices. Hardness and fullness are difficult to release; Di Dang Tang is necessary. With exterior symptoms still present, using Di Dang Tang entirely ignores the exterior because the pathogen is severe in the interior, requiring immediate rescue of the interior. With exterior symptoms resolved, Tao Ren Cheng Qi Tang retains Gui Zhi (Cinnamon Twig) because the pathogen is severe in the exterior, requiring protection of the exterior.
Tao Ren Cheng Qi Tang Formula:
Tao Ren (Peach Kernel) - 50 units.
Gan Cao (Licorice Root) - 2 liang.
Gui Zhi (Cinnamon Twig) - 2 liang.
Mang Xiao (Mirabilite) - 2 liang.
Da Huang (Rhubarb Root) - 4 liang.
These five ingredients are boiled in 7 sheng of water to obtain 2.5 sheng. Strain, add Mang Xiao, boil briefly over fire. Remove from fire. Take 5 he warm before meals, three times daily. Mild purgation should occur.
In Yangming disease, if the patient suffers from forgetfulness, there must be Blood Accumulation. The reason is that there was originally long-standing stasis-blood, causing forgetfulness. Although feces are hard, defecation is surprisingly easy, and the color is definitely black. Di Dang Tang should be used to purge.
Stasis-blood is the root of the disease; forgetfulness is the manifestation. This describes symptoms prior to Yangming disease becoming apparent. Previously unknown, now investigated due to Yangming disease. Hard feces indicate Yangming disease. Hardness usually makes defecation difficult, but here it is easy, revealing a change in pathogenesis. Investigating the cause reveals old blood, as Blood moistens. Old blood turns black, representing Fire extreme transforming into Water imagery. By observing the ease of defecation and investigating the black color, the root of the disease is found, explaining the prior forgetfulness. Cheng Qi formulas are Yangming medicines. Tao Ren Cheng Qi Tang is not used because defecation is easy (no need for Mang Xiao); there is no exterior symptom (no Gui Zhi); stasis is old (no Gan Cao needed). Only Meng Chong and Shui Zhi can handle this task.
A patient with no exterior or interior symptoms presents with fever and constipation for seven or eight days. Even if the pulse is floating and rapid, purgation is permissible. Suppose purgation has been performed, but the rapid pulse persists. Combined heat causes efficient digestion and hunger. After six or seven days of constipation again, there is Blood stasis. Di Dang Tang is suitable. If the rapid pulse persists but diarrhea continues incessantly, it will likely involve heat and pus/blood in the stool.
No headache or aversion to cold indicates no exterior symptom. No irritability, vomiting, or thirst indicates no interior symptom, though heat exists. After seven or eight days, constipation should be expected. Thus, even with a floating-rapid pulse, purgation is logical, as seen by continued constipation post-purgation. "Combined heat" and "cooperating heat" refer to internal and external heat. The previous clause deduced origin from symptoms; this clause differentiates symptoms from pulse. Extreme heat in exterior and interior, with Excess Yang and Deficient Yin, damages the Yin collaterals. Continued constipation indicates Blood Accumulation. Heat-induced diarrhea indicates pus and blood in stool. Huang Lian E Jiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is suitable. The previous case, with easy defecation, showed long-standing stasis, verified by formed symptoms. This case, with continued constipation, shows newly formed stasis, predicted by unformed symptoms. Among the Six Channels, only Taiyang and Yangming have Blood Accumulation syndromes because these two channels have abundant Blood. Thus, pulses and symptoms differ, but treatment principles are the same.
Taiyang cooperating-heat diarrhea can be deficient or excess-heat. Yangming is excess-heat without deficiency. Shaoyin pus/blood in stool is deficient; Yangming is heat. Rapid pulse indicates deficient heat, which cannot digest food efficiently. Efficient digestion and hunger indicate excess-heat.