伤寒有本病。有变病。本病者。如太阳有头痛、项强。阳明有潮热、谵语是也。治法不
外本经。故即附于本经之下。变病者。本不应有此病。只因治不中 。或迁延日久。
而变生诸症。如蓄血、结胸等症是也。治法不得不随症用药。因病施治。用列于左。以尽伤寒之变。
衄血者。血从鼻中来也。伤寒衄血。其因有三。太阳失表。热瘀于经而衄者。有头疼、
目瞑之征。宜清解之。羚羊角、黑栀子、连翘、赤芍、丹皮、元参、薄荷、黑荆芥、鲜生地、牛
膝、泽泻、茅根之属。降之清之。不可再汗也。阳明失下。热瘀于里而衄者。有漱水不
欲咽之征。宜下解之。生地、赤芍、丹皮、牛膝、楂肉、桃仁、大黄之属。下之清之。此釜底
抽薪。大黄不妨重用也。更有温热之症。药宜凉解。误用辛温而动经血。亦能致衄。
宜清血分。犀角、连翘、赤芍、丹皮、元参、生地、牛膝、茜根、茅根之属。清之解之。如衄后
身凉脉静。邪从红汗而解也。若衄后病势反剧者。更伤其阴也。大为危候。其衄势
必重。须大剂六味饮。加麦冬、五味主之。衄止则生。有衄势太甚。阳随阴走。四肢厥
冷者。六味加牛膝、肉桂以镇之。
仲景论云。若头痛者。必衄。宜桂枝汤。此桂枝汤补在上文当须发汗下。又云。剧者
必衄。衄乃解。麻黄汤主之。此麻黄汤补在上文当发其汗下。乃古人倒笔法。是申
明致衄之由于失表。非谓衄后服麻黄桂枝也。观下文衄家不可发汗之戒。义可知矣。
伤寒病有本病，有变病。所谓本病，例如太阳经受邪出现头痛、项背强直；阳明经受邪出现潮热、说胡话等，就是本病。治疗原则不离本经的治法，所以附在本经条文之下。所谓变病，是指原本不应出现的病症，只因为治疗不当，或者拖延日久，从而变化生出各种症状，如蓄血证、结胸证等就是变病。治疗必须随症用药，因病施治，现列举如下，以穷尽伤寒病的各种变化。
衄血，是指血液从鼻腔流出。伤寒引起的衄血，原因有三类：一是太阳表证失于发汗解表，热邪瘀滞于经络而致衄血，伴有头痛、眼睛闭合不想睁开等症状，宜用清热解表法。药用羚羊角、黑栀子、连翘、赤芍、牡丹皮、玄参、薄荷、黑荆芥、鲜生地、牛膝、泽泻、白茅根之类。采用降逆清热的治法，不可再用发汗法。二是阳明里证失于攻下，热邪瘀滞于体内而致衄血，伴有想漱口但不想吞咽等症状，宜用攻下清热法。药用地黄、赤芍、牡丹皮、牛膝、山楂肉、桃仁、大黄之类。采用攻下清热的治法，这是釜底抽薪之法，大黄不妨重用。三是更有温热性质的病症，用药应当清凉解表，如果误用辛温药物扰动经络之血，也能导致衄血。宜用凉血清热法。药用犀角、连翘、赤芍、牡丹皮、玄参、地黄、牛膝、茜草根、白茅根之类。采用清解血分郁热的方法。如果衄血后身体凉爽、脉搏平静，说明邪气随着“红汗”（衄血）而解除。如果衄血后病情反而加重，是进一步损伤了阴液，属于非常危险的征候。此时衄血量必然很大，需用大剂量的六味地黄丸，加麦冬、五味子来主治。衄血停止则生机可保。如果有衄血势头太猛，阳气随着阴血脱失，出现四肢厥冷的情况，用六味地黄丸加牛膝、肉桂来镇摄收敛。
张仲景在论述中说：“如果头痛的，一定会衄血，宜用桂枝汤。”这里的桂枝汤补注位于上文“当须发汗”条之下。又说：“病情严重的，一定会衄血，衄血后病愈，主方用麻黄汤。”这里的麻黄汤补注位于上文“当发其汗”条之下。这是古人倒叙的笔法，是为了阐明导致衄血的原因是由于失于解表，并不是说衄血之后服用麻黄汤或桂枝汤。看下文关于“衄家不可发汗”的禁忌，其中的义理就可以知道了。
Shaoyang disease (Taiyang disease) has its primary manifestation and its secondary manifestations. The primary manifestation refers to conditions such as headache and stiffness of the neck and back in Taiyang disease, or tidal fever and delirium in Yangming disease. The treatment principles do not deviate from the methods specific to the affected meridian; therefore, these are appended under the respective meridian sections. Secondary manifestations refer to symptoms that should not originally be present, arising only due to improper treatment or prolonged delay, leading to various complications such as Blood Stasis Syndrome (Xue Yu) or Chest Binding Syndrome (Jie Xiong). Treatment must be tailored to the specific symptoms and the nature of the disease. These are listed below to exhaustively cover the variations of Shaoyang disease.
Epistaxis (Nu Xue) refers to bleeding from the nose. In Shaoyang disease, epistaxis arises from three causes:
1. When Taiyang exterior syndrome is neglected and not resolved through sweating, heat stagnates in the meridians causing epistaxis. Signs include headache and a desire to keep the eyes closed. Clearing and resolving the heat is indicated. Herbs include Antelope Horn (Ling Yang Jiao), Black Gardenia (Hei Zhi Zi), Forsythia (Lian Qiao), Red Peony Root (Chi Shao), Moutan Bark (Dan Pi), Scrophularia Root (Yuan Shen), Mint (Bo He), Black Schizonepeta (Hei Jing Jie), Fresh Rehmannia Root (Xian Sheng Di), Achyranthes Root (Niu Xi), Alisma (Ze Xie), and Sedge Rhizome (Mao Gen). The method involves descending and clearing; diaphoresis (sweating) must not be used again.
2. When Yangming interior syndrome is neglected and not purged, heat stagnates in the interior causing epistaxis. Signs include rinsing the mouth with water but no desire to swallow. Purging and clearing the interior is indicated. Herbs include Rehmannia Root (Sheng Di), Red Peony Root (Chi Shao), Moutan Bark (Dan Pi), Achyranthes Root (Niu Xi), Hawthorn Fruit (Zha Rou), Peach Kernel (Tao Ren), and Rhubarb (Da Huang). The method involves purging and clearing; this is akin to removing firewood from under the cauldron, so Rhubarb may be used in heavy doses.
3. In cases of Warm-Heat diseases, cooling and resolving agents are appropriate. If acrid-warm herbs are mistakenly used, they may disturb the blood in the meridians, also leading to epistaxis. Clearing the blood level is indicated. Herbs include Rhinoceros Horn (Xi Jiao - *Note: Substitute with Buffalo Horn in modern practice*), Forsythia (Lian Qiao), Red Peony Root (Chi Shao), Moutan Bark (Dan Pi), Scrophularia Root (Yuan Shen), Rehmannia Root (Sheng Di), Achyranthes Root (Niu Xi), Rubia Root (Qian Gen), and Sedge Rhizome (Mao Gen). The method involves clearing and resolving. If the body becomes cool and the pulse calm after epistaxis, it indicates that the pathogenic factor has been expelled via "red sweat" (epistaxis). However, if the condition worsens after epistaxis, it signifies further damage to Yin, which is a critical prognosis. The volume of bleeding will likely be heavy; large doses of Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia) added with Ophiopogon Tuber (Mai Dong) and Schisandra Berry (Wu Wei Zi) should be administered. Life can be preserved if the bleeding stops. If the epistaxis is excessively severe, causing Yang to follow the loss of Yin, resulting in cold limbs, Liuwei Dihuang Wan added with Achyranthes Root (Niu Xi) and Cinnamon Bark (Rou Gui) should be used to anchor and stabilize.
Zhang Zhongjing stated in his treatise: "If there is headache, epistaxis is inevitable; Guizhi Tang (Cinnamon Twig Decoction) is indicated." This note on Guizhi Tang is appended under the section regarding the necessity of inducing sweating earlier in the text. He also stated: "In severe cases, epistaxis occurs, and the disease resolves upon epistaxis; Mahuang Tang (Ephedra Decoction) is indicated." This note on Mahuang Tang is appended under the section regarding the necessity of inducing sweating earlier in the text. This is an inverted narrative technique used by the ancients to clarify that the cause of epistaxis was the failure to resolve the exterior initially, not an indication to administer Mahuang Tang or Guizhi Tang *after* epistaxis has occurred. The principle is evident when considering the subsequent warning against inducing sweating in patients who are prone to epistaxis ("Nu Jia").