杂症门，衄血为里症，宜清里；外感门，衄血为表症，宜散表。故曰外感衄血，邪热在经，
但有经络之分，总无寒热之异，同归表热而已。三阴经无衄血，惟阳邪传入少阴，厥而无汗
之症，医者见其手足冷而无汗，误认太阳表邪未伸，用麻桂强发其汗，阴血内动血从口鼻而
出，名下厥上竭。此少阴里热，误用辛温，触动阴血而上冲者也。戴氏云∶仲景论衄血宜发
汗，麻黄汤主之。此治冬月伤寒，太阳表症，里无积热之衄，非言三时热令也。三时衄血，
即有太阳表症，宜散表，只用羌活冲和汤，不可用麻黄桂枝汤。若太阳之邪，已经侵入阳
明，即要与阳明药互用。若阳明本经热甚以致衄者，不用太阳之药，当用升麻干葛汤，以解
阳明气分之邪，随用茅花汤合黄芩芍药汤、犀角地黄汤、升麻清胃汤、以解阳明血分之热。
海藏云∶仲景言衄家不可发汗，汗之必额上陷，此为脉微里有热者言也。夫衄家脉浮紧，可
发汗。若脉已微，表症已解，再发汗，则额上陷。故《伤寒论》云∶衄血脉已微者，用黄芩芍
药汤、犀角地黄汤。此言里热衄血，宜凉血，不可用辛温发散也。吴氏云∶衄血之症，若脉
浮紧，宜发汗；脉不浮紧，不可发汗。东垣治衄血，脉已微，黄芩芍药汤；脉沉数，犀角地
黄汤。余按仲景用麻黄汤治衄，乃是太阳经寒邪未散，脉浮紧之衄；东垣用黄芩芍药汤治
衄，乃是表散血热，脉不浮紧而微者。黄芩凉血，芍药敛血、凉血。敛血则衄自止，再按用
犀角地黄汤治衄者，是表邪解，脉沉数，里热甚，宜清热之衄也。夫犀角地黄，凉阳明血
热，又清肝肾之火，沉数之脉，热在下焦，清肝肾下焦之火，血不上升，而衄不作。故仲景
麻黄汤，但治冬月太阳表邪之衄；东垣黄芩犀角汤，治四时里热之衄，兼治内伤之衄。地黄
引子、门冬引子，治内伤不治外感者。升麻清胃汤，治外感兼治内伤者。此治之分别也。外
感之衄，脉大者易治，沉涩者难医；内伤之衄，脉缓者易治，脉数者难医。此脉之分别也。
太阳病，脉浮无汗，发热身疼，八九日不解，表症仍在，此当发其汗，服药已微除。其人发
烦目瞑，剧者必衄，衄乃解。所以然者，阳气重故也。麻黄汤主之。
太阳病脉浮紧，无汗，发热身疼痛，八九日不解。表邪不散，当以麻黄汤发其汗。今服麻
黄药，已病微除，其人发烦目瞑，剧则太阳之邪，不从汗解，必发鼻衄而解。其所以然之
故，以太阳经热邪重，今得麻黄辛温，必上从阳明入目络鼻之窍而出血矣。麻黄汤主之五
字，在当发汗之下，不然，阳气太重，必衄乃解之后，何可再用麻黄汤也。
太阳病，脉浮紧，发热身无汗，自衄者愈。
此言太阳发热，脉紧无汗，应用麻黄汤。因其人邪微正旺，未服麻黄汤自衄而病愈。申明
上章衄而病解，不必再用麻黄汤也。
太阳伤寒，脉浮紧，不发汗，因致衄者，麻黄汤主之。
上章既明不可多用麻黄汤，此条言失用麻黄汤，因而致衄，太阳症仍在，仍用麻黄汤，申
明致衄后，太阳表邪不解，仍要发表。
太阳病中风，以火劫发汗，邪风被火热，血气流溢，失其常度。两阳相熏灼，其身发黄，阳
盛则欲衄，阴虚则小便难，阴阳俱虚，身体枯燥。
太阳伤寒未发热，火劫发汗，尚不为害。太阳中风，阳邪症火劫，则邪热被火热，血气妄
溢，失其常度，其身必发黄。火伤于上，阴血足者，尚能作衄而解；火伤于下，阴血亏损
者，必致小便不利，阴阳皆虚，而肌肉消烁。
阳明病，口燥但漱水，不欲下咽，此必衄。
此明鼻衄之症，非独太阳之邪，侵入阳明。阳明本经，亦有成衄者。如阳明病口燥，但欲
漱水在口，不欲咽下，此阳明热在血分，亦必发衄。
脉浮发热，口干鼻燥，能食者则衄。
脉浮发热，阳明表热；口鼻干燥能食，阳明里热。表里皆热，则迫血妄行为衄。
升麻干葛汤 见烦躁。
茅根汤 茅花一味。
茅性清凉，根能凉血止烦，花苗专凉上焦之血，故治衄。
黄芩芍药汤
黄芩 白芍药 川连 甘草
阳明表热而衄，前方升麻葛根汤；阳明表热而衄，用此汤，家秘加生地、当归，以当归辛
散，同芩、连、生地，则血凉而当归经矣。
犀角地黄汤
生犀角 山栀 白芍药 荆芥 牡丹皮 赤芍药 生地 黄芩
此方不独治衄，兼治咳血吐血；不独治内伤肝肾血，即阳明外感亦当从此方出入加减。加
黄芩、荆芥，则血凉不上升；若大便实者，加当归、酒蒸大黄，其血立刻归经。家秘用当
归同凉血药则下顺归经之功最大。
地黄饮子
生地 丹皮 天门冬 黄芩 地骨皮 白芍
此治肝肾精竭，血燥劳瘵之方。若尺脉大，加黄柏、知母。以外感发衄，皆因本元血分有
火，故亦立此方。
门冬饮子
麦门冬 地骨皮 知母 石膏 生地 丹皮 白芍药
此通治鼻血之方。若阳明表症，加升麻、干葛、荆芥、黄芩；若里热便结，加当归、大黄。
干葛石膏汤
干葛 石膏 知母 甘草 丹皮 生地 黄芩
此方专治外感衄血者。然此凉阳明气分之药，家秘加丹皮、生地、黄芩，则兼凉其血。
升麻清胃汤 见口渴。
衄血，皆阳明血中伏火。故以此方清阳明血分之热。
在杂病门类中，衄血（鼻出血）属于里证，适宜清解里热；在外感病门类中，衄血属于表证，适宜发散表邪。所以说外感引起的衄血，是邪热在经络，虽然有经络部位的区别，但总没有寒证与热证的差异，都归属于表热范畴。三阴经（太阴、少阴、厥阴）通常不发生衄血，只有当阳邪传入少阴经，出现四肢厥冷且无汗的症状时，医生见到患者手足冰冷且无汗，误认为是太阳经表邪未得舒展，便使用麻黄汤和桂枝汤强行发汗，导致阴血在内扰动，血液从口鼻流出，这种情况称为“下厥上竭”（下部阳气厥逆，上部阴血枯竭）。这是少阴经的里热，误用了辛温药物，触动阴血而上冲所致。戴氏说：张仲景论述衄血宜用发汗法，以麻黄汤为主治方剂。这是治疗冬季伤寒，太阳经表证，体内没有积热的衄血，并非指春、夏、秋三季的热令时节。在三季发生的衄血，即使有太阳经表证，也宜发散表邪，只用羌活冲和汤，不可使用麻黄汤或桂枝汤。如果太阳经的邪气已经侵入阳明经，就要将治疗太阳经的药物与治疗阳明经的药物配合使用。如果是阳明本经热盛导致的衄血，不使用治疗太阳经的药物，应当使用升麻干葛汤，以解除阳明经气分的邪热，随后使用茅花汤合黄芩芍药汤、犀角地黄汤、升麻清胃汤，以解除阳明经血分的内热。
海藏说：张仲景言患有衄血病史的人不可发汗，若发汗必然导致额部凹陷，这是针对脉象微弱、里有热者而言的。如果衄血患者的脉象浮紧，是可以发汗的。如果脉象已经微弱，表证已经解除，再发汗，就会导致额部凹陷。所以《伤寒论》说：衄血后脉象已微弱的，使用黄芩芍药汤、犀角地黄汤。这是说里热引起的衄血，适宜凉血，不可使用辛温发散的药物。吴氏说：衄血的病症，如果脉象浮紧，宜发汗；脉象不浮紧，不可发汗。东垣治疗衄血，脉象已微弱的，用黄芩芍药汤；脉象沉数（深沉而快速），用犀角地黄汤。我按语认为：张仲景使用麻黄汤治疗衄血，乃是太阳经寒邪未散，脉象浮紧的衄血；东垣使用黄芩芍药汤治疗衄血，乃是表散血热，脉象不浮紧而微弱的情况。黄芩能凉血，芍药能敛血、凉血。收敛血液则衄血自然停止。再按：使用犀角地黄汤治疗衄血的，是表邪已解，脉象沉数，里热甚盛，适宜清热治疗的衄血。犀角地黄汤，能凉解阳明经的血热，又能清泻肝肾之火。脉象沉数，说明热在下焦，清泻肝肾及下焦之火，血液就不会上升，衄血也就不会发生。所以张仲景的麻黄汤，只治疗冬季太阳经表邪引起的衄血；东垣的黄芩汤和犀角地黄汤，治疗四季里热引起的衄血，兼治内伤引起的衄血。地黄饮子和门冬饮子，治疗内伤而不治疗外感。升麻清胃汤，治疗外感兼治内伤。这是治疗上的区别。外感引起的衄血，脉象大的容易治疗，脉象沉涩的难治；内伤引起的衄血，脉象缓的和缓的容易治疗，脉象数的快速的难治。这是脉象上的区别。
太阳病，脉象浮，无汗，发热身疼，经过八九天仍未解除，表证仍在，这应当发其汗，服药后症状轻微缓解。其人感到心烦，眼睛闭合不想睁开，严重的必定衄血，衄血后病愈。之所以这样，是因为阳气郁重所致。主治方为麻黄汤。
太阳病，脉象浮紧，无汗，发热身疼痛，经过八九天仍未解除。表邪未散，应当用麻黄汤发其汗。现在服用麻黄药后，病情已轻微缓解，其人感到心烦，眼睛闭合不想睁开，严重时太阳经的邪气，不从汗液排出，必定通过鼻衄而解除。其所以这样的原因，是因为太阳经热邪重，现在得到麻黄的辛温之性，必定向上从阳明经进入目络和鼻窍而出血。原文中“麻黄汤主之”五个字，应当在“当发汗”之下，否则，阳气太重，必定衄血后才解除，之后怎么还能再用麻黄汤呢？
这是说太阳病发热，脉紧无汗，应用麻黄汤。因为此人邪气轻微正气旺盛，未服麻黄汤就自行衄血而病愈。申明上一章衄血后病解，不必再用麻黄汤。
上一章既然明确了不可多用麻黄汤，此条说明失用麻黄汤，因而导致衄血，太阳症仍在，仍用麻黄汤，申明致衄后，太阳经表邪未解，仍然需要发表。
太阳病中风，用火法劫迫发汗，邪风被火热所伤，血气流溢，失去常度。两阳（风邪与火热）相互熏灼，身体发黄，阳盛则想要衄血，阴虚则小便困难，阴阳俱虚，身体干枯粗糙。
太阳伤寒尚未发热，用火法劫迫发汗，尚且不造成危害。太阳中风，阳邪症候用火法劫迫，则邪热被火热所助，血气妄行溢出，失去常度，身体必定发黄。火邪伤于上，阴血充足者，尚能作衄血而解除；火邪伤于下，阴血亏损者，必定导致小便不利，阴阳皆虚，肌肉消烁。
这是阐明鼻衄的病症，不仅仅是太阳经的邪气侵入阳明经。阳明本经，也有形成衄血的。如阳明病口燥，只想含水在口中，不想咽下，这是阳明热在血分，也必定发衄。
脉象浮发热，是阳明经表热；口鼻干燥能食，是阳明经里热。表里皆热，则逼迫血液妄行为衄血。
升麻干葛汤 见烦躁章节。
茅根汤 仅用茅花一味药。
茅草性清凉，根部能凉血止烦，花苗专门凉解上焦的血热，所以治疗衄血。
黄芩芍药汤
组成：黄芩、白芍药、川连、甘草。
阳明经表热而衄血，前方用升麻葛根汤；阳明经表热而衄血，用此汤，家秘（作者自注）加生地、当归，因为当归辛散，同芩、连、生地配合，则血凉而当归引导血液归经。
犀角地黄汤
组成：生犀角、山栀、白芍药、荆芥、牡丹皮、赤芍药、生地、黄芩。
此方不仅治疗衄血，兼治咳血吐血；不仅治疗内伤肝肾血热，即使是阳明经外感也应当从此方出入加减。加黄芩、荆芥，则血凉不上升；如果大便干结者，加当归、酒蒸大黄，血液立刻归经。家秘用当归同凉血药配合，则下顺归经的功效最大。
地黄饮子
组成：生地、丹皮、天门冬、黄芩、地骨皮、白芍。
此方治疗肝肾精竭，血燥劳瘵的方剂。如果尺脉大，加黄柏、知母。因为外感发衄，皆因本元血分有火，所以也设立此方。
门冬饮子
组成：麦门冬、地骨皮、知母、石膏、生地、丹皮、白芍药。
此方通治鼻血的方剂。如果有阳明经表症，加升麻、干葛、荆芥、黄芩；如果里热便结，加当归、大黄。
干葛石膏汤
组成：干葛、石膏、知母、甘草、丹皮、生地、黄芩。
此方专治外感衄血者。然而这是凉解阳明经气分的药物，家秘加丹皮、生地、黄芩，则兼凉其血。
升麻清胃汤 见口渴章节。
In the category of miscellaneous diseases, epistaxis (nosebleed) is considered a interior syndrome, suitable for clearing interior heat; in the category of external contraction diseases, epistaxis is considered an exterior syndrome, suitable for dispersing exterior pathogens. Therefore, it is said that epistaxis caused by external contraction involves pathogenic heat in the meridians. Although there are distinctions among different meridians, there is no fundamental difference between cold and heat syndromes; they all return to exterior heat. The Three Yin meridians (Taiyin, Shaoyin, Jueyin) typically do not present with epistaxis. Only when Yang pathogens transmit into the Shaoyin meridian, presenting with limb coldness and anhidrosis (absence of sweating), might a physician, seeing cold hands and feet without sweat, mistakenly recognize it as unextended Taiyang exterior pathogens, and use Mahuang Tang (Ephedra Decoction) or Guizhi Tang (Cinnamon Twig Decoction) to forcibly induce sweating. This agitates Yin blood internally, causing blood to flow from the mouth and nose, a condition termed "Jue at the bottom and exhaustion at the top" (lower Yang collapse and upper Yin depletion). This results from interior heat in the Shaoyin meridian being mishandled with acrid-warm herbs, stirring up Yin blood to rush upward. Dai stated: Zhang Zhongjing discussed treating epistaxis with diaphoresis, using Mahuang Tang as the primary formula. This treats winter cold damage, Taiyang exterior syndrome, where there is no accumulated interior heat causing epistaxis, and does not refer to the hot seasons of spring, summer, and autumn. In these three seasons, even if Taiyang exterior symptoms exist, one should disperse the exterior using Qianghuo Chonghe Tang, and must not use Mahuang Tang or Guizhi Tang. If Taiyang pathogens have already invaded the Yangming meridian, Taiyang and Yangming treatments should be combined. If epistaxis is caused by severe heat in the Yangming meridian itself, Taiyang herbs should not be used; instead, Shengma Gange Tang should be used to resolve Qi-level pathogens in the Yangming meridian, followed by Maohua Tang combined with Huangqin Shaoyao Tang, Xijiao Dihuang Tang, or Shengma Qingwei Tang to resolve Blood-level heat in the Yangming meridian.
Haizang stated: Zhang Zhongjing said that patients with a history of epistaxis should not undergo diaphoresis; doing so will cause depression of the forehead. This refers to cases with a faint pulse and interior heat. If a patient with epistaxis has a floating-tight pulse, diaphoresis is permissible. However, if the pulse has become faint and the exterior syndrome has resolved, further diaphoresis will cause forehead depression. Thus, the *Shanghan Lun* states: For epistaxis with a now-faint pulse, use Huangqin Shaoyao Tang and Xijiao Dihuang Tang. This indicates that epistaxis due to interior heat requires cooling the blood, and acrid-warm dispersing methods are contraindicated. Wu stated: For epistaxis, if the pulse is floating-tight, diaphoresis is indicated; if not, it is contraindicated. Dongyuan treated epistaxis with a faint pulse using Huangqin Shaoyao Tang, and with a deep-rapid pulse using Xijiao Dihuang Tang. My commentary notes: Zhang Zhongjing’s use of Mahuang Tang for epistaxis applies to Taiyang cold pathogens that have not dispersed, presenting with a floating-tight pulse; Dongyuan’s use of Huangqin Shaoyao Tang applies to dispersing Blood heat when the pulse is not floating-tight but faint. Huangqin cools blood, and Shaoyao astringes and cools blood. Astringing the blood stops epistaxis naturally. Furthermore, the use of Xijiao Dihuang Tang applies to cases where exterior pathogens have resolved, the pulse is deep-rapid, and interior heat is severe, requiring heat-clearing treatment. Xijiao Dihuang Tang cools Yangming Blood heat and clears Fire from the Liver and Kidneys. A deep-rapid pulse indicates heat in the Lower Jiao; clearing Liver/Kidney and Lower Jiao Fire prevents blood from rising, thus preventing epistaxis. Therefore, Zhang Zhongjing’s Mahuang Tang treats only winter Taiyang exterior epistaxis; Dongyuan’s Huangqin Tang and Xijiao Dihuang Tang treat interior heat epistaxis in all four seasons, and also treat internal injury epistaxis. Dihuang Yinzi and Mendong Yinzi treat internal injury, not external contraction. Shengma Qingwei Tang treats external contraction and also internal injury. This is the distinction in treatment. For external contraction epistaxis, a large pulse is easy to treat, while a deep-choppy pulse is difficult; for internal injury epistaxis, a slow pulse is easy to treat, while a rapid pulse is difficult. This is the distinction in pulses.
Taiyang disease, with a floating pulse, anhidrosis, fever, and body pain, persisting for eight to nine days without resolution, indicates the exterior syndrome remains. Diaphoresis is indicated. After medication, symptoms may slightly improve. The patient may feel vexed and desire to keep eyes closed; severely, epistaxis occurs, leading to recovery. This occurs because Yang Qi is heavily constrained. Mahuang Tang is the primary formula.
Taiyang disease, with a floating-tight pulse, anhidrosis, fever, and body pain, persisting for eight to nine days without resolution. Exterior pathogens remain undispersed; Mahuang Tang should be used to induce sweating. If the patient takes Mahuang Tang and symptoms slightly improve, but then becomes vexed and desires to keep eyes closed, severe cases will see Taiyang pathogens exit via epistaxis rather than sweat. This is because Yangming heat pathogens are heavy; the acrid-warm nature of Mahuang causes them to exit upward through the Yangming meridian, eye collaterals, and nasal orifices. The phrase "Mahuang Tang is the primary formula" should appear after "diaphoresis is indicated"; otherwise, if Yang Qi is too heavy, epistaxis resolves the condition, making subsequent use of Mahuang Tang inappropriate.
Taiyang disease, with a floating-tight pulse, fever, and anhidrosis, resolves spontaneously upon epistaxis.
This explains that for Taiyang fever, tight pulse, and anhidrosis, Mahuang Tang is indicated. However, if the patient’s pathogen is mild and Zheng Qi is strong, spontaneous epistaxis cures the disease without medication. This clarifies that after epistaxis resolves the syndrome, Mahuang Tang need not be used again.
Taiyang cold damage, with a floating-tight pulse, if not treated with diaphoresis and resulting in epistaxis, Mahuang Tang is the primary formula.
Having established that Mahuang Tang should not be overused, this clause states that failure to use Mahuang Tang initially leads to epistaxis. Since Taiyang symptoms persist, Mahuang Tang is still indicated, clarifying that even after epistaxis, if Taiyang exterior pathogens remain, exterior release is still necessary.
Taiyang Wind Strike, treated with fire therapy to force sweating, allows wind pathogens to combine with fire heat. Blood and Qi overflow, losing their normal course. The combination of two Yangs (wind and fire) scorching the body causes jaundice. Excess Yang leads to impending epistaxis; Yin deficiency leads to difficult urination. With both Yin and Yang deficient, the body becomes dry and rough.
Taiyang Cold Damage without fever, treated with fire therapy, causes little harm. However, Taiyang Wind Strike with fire therapy exacerbates Yang pathogens with fire heat, causing blood and Qi to overflow abnormally. Jaundice ensues. Fire injuring the upper jiao: if Yin blood is sufficient, epistaxis may occur to resolve the condition. Fire injuring the lower jiao: if Yin blood is depleted, urinary difficulty ensues, Yin and Yang both become deficient, and muscles waste away.
Yangming disease, with dry mouth desiring only to rinse water in the mouth without swallowing, indicates impending epistaxis.
This clarifies that epistaxis is not solely caused by Taiyang pathogens invading Yangming. Yangming meridian itself can cause epistaxis. For example, Yangming disease with dry mouth, desiring only to hold water in the mouth without swallowing, indicates heat in the Blood level of Yangming, which will likely cause epistaxis.
Floating pulse, fever, dry mouth and nose, and ability to eat indicate impending epistaxis.
Floating pulse and fever indicate Yangming exterior heat; dry mouth/nose and ability to eat indicate Yangming interior heat. Heat in both exterior and interior forces blood to overflow, causing epistaxis.
Shengma Gange Tang: See section on Vexation.
Maogen Tang: Consists of only Maohua (reed catkins).
Reed is cool in nature; its root cools blood and relieves vexation; its flowers specifically cool Upper Jiao blood heat, hence treating epistaxis.
Huangqin Shaoyao Tang
Ingredients: Huangqin (Scutellaria Root), Baishao Yao (White Peony Root), Chuanlian (Coptis Rhizome), Gancao (Licorice Root).
For Yangming exterior heat with epistaxis, the previous formula Shengma Gange Tang is used; for Yangming exterior heat with epistaxis, this formula is used. My secret addition includes Shengdi (Rehmannia Root) and Danggui (Angelica Sinensis). Because Danggui is acrid and dispersing, combined with Huangqin, Lian, and Shengdi, it cools blood and guides it back to the vessels.
Xijiao Dihuang Tang
Ingredients: Sheng Xijiao (Fresh Rhinoceros Horn - note: substitute with Water Buffalo Horn in modern practice), Shanzhi (Gardenia Fruit), Baishao Yao (White Peony Root), Jingjie (Schizonepeta Spike), Mudanpi (Tree Peony Bark), Chishao Yao (Red Peony Root), Shengdi (Rehmannia Root), Huangqin (Scutellaria Root).
This formula treats not only epistaxis but also hemoptysis and hematemesis; it treats not only Liver/Kidney internal injury blood heat but also Yangming external contraction, requiring modifications based on this base. Adding Huangqin and Jingjie cools blood and prevents upward rushing; if stool is hard, add Danggui and Jiuhuang Da (Rhubarb steamed with wine) to immediately guide blood back to the vessels. Using Danggui with blood-cooling herbs maximizes the effect of guiding blood downward and returning it to the vessels.
Dihuang Yinzi
Ingredients: Shengdi (Rehmannia Root), Danpi (Moutan Cortex), Tianmendong (Asparagus Tuber), Huangqin (Scutellaria Root), Digupi (Lycium Bark), Baishao (White Peony Root).
This formula treats exhaustion of Liver/Kidney essence, blood dryness, and consumptive disease. If the Chi pulse is large, add Huangbai (Phellodendron Bark) and Zhimu (Anemarrhena Rhizome). External contraction epistaxis often stems from fire in the original Yuan Blood level, hence this formula is established.
Mendong Yinzi
Ingredients: Maimendong (Ophiopogon Tuber), Digupi (Lycium Bark), Zhimu (Anemarrhena Rhizome), Shigao (Gypsum Fibrosum), Shengdi (Rehmannia Root), Danpi (Moutan Cortex), Baishao Yao (White Peony Root).
This formula generally treats nasal bleeding. If Yangming exterior symptoms exist, add Shengma, Gange, Jingjie, and Huangqin; if interior heat with constipation exists, add Danggui and Dahuang.
Gange Shigao Tang
Ingredients: Gange (Pueraria Lobata Root), Shigao (Gypsum Fibrosum), Zhimu (Anemarrhena Rhizome), Gancao (Licorice Root), Danpi (Moutan Cortex), Shengdi (Rehmannia Root), Huangqin (Scutellaria Root).
This formula specializes in treating external contraction epistaxis. It cools Yangming Qi-level heat; my addition of Danpi, Shengdi, and Huangqin extends its action to cool Blood heat.
Shengma Qingwei Tang: See section on Thirst.
Epistaxis is caused by latent fire in the Yangming Blood. Thus, this formula clears heat from the Yangming Blood level.