杂病衄血，责热在里；伤寒衄血，责热在表。《论》曰∶伤寒小便清者，知不在里，仍在表也
，当发其汗；若头痛者，必衄，宜桂枝汤。曰∶伤寒脉浮紧，不发汗，因致衄者，麻黄汤主之。此
以伤寒之衄，为其热不在里，在表而然也。然又《论》曰∶衄家不可发汗。而何以复用桂枝、麻黄
等汤？盖衄由乎阴者，以阴虚火动也，故不宜再汗以亡阴；衄由乎阳者，以表邪未解也，故当用桂
枝、麻黄以发散。又《论》曰∶太阳病，脉浮紧，发热，身无汗，自衄者愈。此以表邪欲解，不从
汗而从血，俗人谓之红汗，所以衄后当愈也。由此观之，则有因衄而愈者，以经通而邪散也；有治
衄仍当发散者，以邪之将解未解，而因散其余邪也。治衄之法，于斯可见。若寒气不甚，而用麻黄
、桂枝，似属太刚，或易以柴葛之类，自无不可，用者其酌之。
《论》曰∶阳明病，口燥但欲漱水，不欲咽者，此必衄。盖阳明之脉络于口鼻，今其漱水不欲
咽者，以热在经而里无热，故当鼻衄也。
一、有动阴血者，又非衄血之谓。《论》曰∶少阴病，但厥无汗，而强发之，必动其血，未知
从何道出，故或从口鼻，或从目出者，是名下厥上竭。此阴血也，乃为危证。
伤寒蓄血者，以热结在里，搏于血分，留瘀下焦而不行也。《论》曰∶伤寒有热，少腹满，应
小便不利，今反利者，为有血也。又曰∶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，血证谛也。大抵热蓄血分，留结下焦则生狂躁，《论》曰∶热结膀胱，其
人如狂者是也。然又有阳明证，其人喜忘，屎虽硬，而大便反快，其色黑者，是亦蓄血之证。故凡
诊伤寒，但其少腹硬满而痛，盒饭问其小便，若小水自利者，知为蓄血之证，盖小水由于气化，病
在血而不在气，故小便利而无恙也。血瘀于下者，血去则愈，其在仲景之法，则以抵当汤、抵当丸
主之。愚谓但以承气之类，加桃仁、红花以逐之，或其兼虚者，以玉烛散之类下之，则蓄血自去，
而病无不除矣。
成无己曰∶伤寒衄者，以邪气不得发散，壅盛于经，逼迫于血，因而致衄也。蓄血者，下焦结
聚，而不行不散也。血菀于上而吐血者，谓之薄厥，留瘀于下者，谓之蓄血。此由太阳经瘀热在里
，搏蓄下焦所致。
《经》曰∶太阳病七八日，表证仍在，脉沉而微，反不结胸，其人如狂者，以热在下焦，少腹
当硬满，小便自利者，下血乃愈。
杂病引起的鼻出血，病机在于里有热；伤寒引起的鼻出血，病机在于表有热。《伤寒论》中说：伤寒病患者小便清长，说明病邪不在里，仍在表，应当用发汗法治疗；如果伴有头痛，必然会出现鼻出血，适宜用桂枝汤治疗。又说：伤寒患者脉象浮紧，若未及时发汗，导致出现鼻出血的，以麻黄汤主治。这是说伤寒引起的鼻出血，是因为热邪不在里，而在表所致。然而《伤寒论》中又说：经常鼻出血的人（衄家）不可使用发汗法。那为什么又重复使用桂枝汤、麻黄汤呢？大概而言，因阴虚导致的鼻出血，是由于阴虚火旺，所以不宜再次发汗以免耗伤阴液；因表邪未解导致的鼻出血，应当用桂枝汤、麻黄汤来发散表邪。又《伤寒论》中说：太阳病，脉象浮紧，发热，身体无汗，自然发生鼻出血后病就好了。这是因为表邪欲解，病邪不从汗出而从血出，俗人称之为“红汗”，所以鼻出血后病就会痊愈。由此看来，有的因鼻出血而病愈，是因为经络通畅而邪气消散；有的治疗鼻出血仍当用发散法，是因为邪气将解未解，借发散以清除残余邪气。治疗鼻出血的方法，从这里就可以看出来了。如果寒气不重，却使用麻黄、桂枝，似乎过于刚烈，或者改用柴胡、葛根之类的药物，也是完全可以的，使用者自行斟酌。
《伤寒论》中说：阳明病，口干燥只想含水漱口，却不打算咽下，这必然会发生鼻出血。因为阳明的经脉联络口鼻，现在患者想漱口不想咽水，是因为热在经脉而里没有热，所以会导致鼻出血。
一、有一种情况是扰动阴血，这就不是通常所说的鼻出血了。《伤寒论》中说：少阴病，只见四肢厥冷而无汗，如果强行发汗，必然会扰动其血，不知道血液会从哪个孔窍流出，所以有的从口鼻流出，有的从眼睛流出的，这叫作“下厥上竭”。这是阴血受损，属于危重证候。
伤寒蓄血证，是因为热邪结聚在里，与血分相搏，瘀血留滞在下焦而不能运行。《伤寒论》中说：伤寒患者有发热，小腹胀满，按理应该小便不利，现在反而小便通利的，是有瘀血的表现。又说：太阳病，身体发黄，脉象沉涩，小腹部硬满，如果小便不利的，是没有瘀血。如果小便自利，其人神志如狂的，则是确凿的血证。大抵热邪蓄积在血分，留结在下焦就会产生狂躁，《伤寒论》中说：“热结膀胱，其人如狂”就是这种情况。然而又有阳明病的症状，患者健忘，大便虽然干硬，但排便反而顺畅，颜色发黑的，这也是蓄血证的表现。所以凡是诊断伤寒，只要发现小腹部硬满疼痛，就应当询问其小便情况，如果小便自利，就知道是蓄血证，因为小便的通利依赖于气化功能，病在血分而不在气分，所以小便通利而没有其他异常。瘀血在下焦，通过祛除瘀血即可痊愈，这在张仲景的法度中，是以抵当汤、抵当丸为主治方剂。我认为如果只是用承气汤之类的方剂，加入桃仁、红花来逐瘀，或者对于兼有虚证的患者，用玉烛散之类的方剂攻下，那么蓄血自然去除，疾病没有不能治愈的。
成无己说：伤寒引起的鼻出血，是因为邪气不得发散，壅盛于经脉，逼迫血液妄行，因而导致鼻出血。蓄血证，是下焦气血结聚，不能运行消散。血液郁积于上部而吐血，叫作“薄厥”；瘀血留滞于下部，叫作“蓄血”。这都是由太阳经瘀热在里，搏结蓄积于下焦所导致的。
《黄帝内经》中说：太阳病经过七八天，表证仍然存在，脉象沉而微弱，反而没有形成结胸证，患者神志如狂，是因为热邪在下焦，小腹部应当硬满，如果小便自利，通过泻下瘀血才能痊愈。
For epistaxis caused by miscellaneous diseases, the pathology is attributed to heat in the interior; for epistaxis caused by Cold Damage (Shanghan), the pathology is attributed to heat in the exterior. The *Treatise* states: In a patient with Cold Damage, if the urine is clear, it indicates that the pathogen is not in the interior but remains in the exterior, and sweating therapy should be employed; if accompanied by headache, epistaxis will inevitably occur, and Guizhi Tang (Cinnamon Twig Decoction) is appropriate. It also states: In a patient with Cold Damage presenting with a floating and tight pulse, if sweating was not induced initially leading to epistaxis, Mahuang Tang (Ephedra Decoction) should be used. This explains that epistaxis in Cold Damage occurs because the heat is not in the interior but in the exterior. However, the *Treatise* also states: Patients who are prone to epistaxis (Nujia) should not undergo sweating therapy. Then why are Guizhi Tang and Mahuang Tang repeatedly used? Generally speaking, epistaxis resulting from Yin deficiency is due to hyperactivity of fire caused by Yin deficiency, so further sweating should be avoided to prevent the loss of Yin fluids; epistaxis resulting from unresolved exterior pathogens requires the use of Guizhi Tang or Mahuang Tang to disperse the exterior. Furthermore, the *Treatise* states: In Taiyang disease, if the pulse is floating and tight, there is fever, no sweating, and spontaneous epistaxis occurs, the disease resolves. This is because the exterior pathogen is about to resolve; instead of exiting through sweat, it exits through blood, commonly known as "red sweat," so the disease heals after epistaxis. From this, we can see that some cases heal via epistaxis because the meridians become unblocked and the pathogen disperses; in other cases, treatment still requires dispersion because the pathogen is resolving but not yet fully resolved, aiming to scatter residual pathogens. Thus, the methods for treating epistaxis are evident here. If the cold pathogen is not severe, using Mahuang or Guizhi might be too harsh; alternatively, using herbs like Chaihu (Bupleuri Radix) or Gegen (Puerariae Lobatae Radix) would be perfectly acceptable, leaving the choice to the practitioner's discretion.
The *Treatise* states: In Yangming disease, if the mouth feels dry and the patient desires only to rinse water in the mouth without swallowing, epistaxis will inevitably occur. This is because the Yangming meridians connect to the mouth and nose; when the patient rinses water but does not swallow, it indicates heat in the meridians but no heat in the interior, leading to nasal bleeding.
1. There is a condition involving the disturbance of Yin blood, which is distinct from typical epistaxis. The *Treatise* states: In Shaoyin disease, if there is only cold extremities without sweating, and sweating is forcibly induced, it will inevitably disturb the blood. It is unknown from which orifice the blood will exit; thus, it may flow from the mouth and nose or from the eyes. This is termed "Lower Jue and Upper Exhaustion." This involves damage to Yin blood and constitutes a critical syndrome.
Cold Damage with Blood Stasis (Xuxue) occurs when heat binds in the interior, contends with the blood level, and causes stasis to remain stagnant in the Lower Jiao without moving. The *Treatise* states: In a patient with Cold Damage who has fever and abdominal fullness, one should expect difficulty in urination; however, if urination is actually free, it indicates the presence of blood stasis. It also states: In Taiyang disease, if the body is yellow, the pulse is deep and knotted, and the lower abdomen is hard, but urination is difficult, there is no blood stasis. If urination is free and the patient exhibits a manic-like state, the diagnosis of blood stasis is confirmed. Generally, heat accumulating in the blood level and binding in the Lower Jiao generates mania and restlessness, as stated in the *Treatise*: "Heat binding in the Bladder, causing the patient to act like a madman." Additionally, there are Yangming symptoms where the patient suffers from forgetfulness; although the stool is hard, defecation is surprisingly easy, and the color is black; this is also a sign of blood stasis. Therefore, whenever diagnosing Cold Damage, if the lower abdomen is hard, full, and painful, one must inquire about urination. If urination is free, it indicates blood stasis, because urination depends on Qi transformation; since the pathology is in the blood level rather than the Qi level, urination remains normal. For stasis located in the lower part, removing the stasis leads to recovery. According to Zhang Zhongjing's methods, Didang Tang (Must-Drain Decoction) or Didang Wan (Must-Drain Pill) are the primary treatments. I suggest that using Chengqi-class formulas added with Taoren (Persicae Semen) and Honghua (Carthami Flos) to purge stasis, or using Yuzhu San (Jade Candle Powder) to purge in cases with concomitant deficiency, will naturally eliminate blood stasis, ensuring the disease is cured.
Cheng Wuji stated: Epistaxis in Cold Damage occurs because the pathogen cannot be dispersed, becomes congested in the meridians, forces the blood to move recklessly, and thus causes epistaxis. Blood stasis refers to aggregation in the Lower Jiao that fails to move or dissipate. Blood stagnating in the upper part causing hematemesis is called "Bo Jue" (Thin Quake); stasis remaining in the lower part is called "Xuxue" (Accumulated Blood). These result from heat-stasis in the Taiyang meridian binding in the interior and accumulating in the Lower Jiao.
The *Classic* states: After seven or eight days of Taiyang disease, if the exterior syndrome persists, the pulse is deep and faint, and contrary to expectations, no Jie Xiong (Chest Binding) has formed, but the patient acts like a madman, it is because heat is in the Lower Jiao. The lower abdomen should be hard and full. If urination is free, purging blood will lead to recovery.