阴乘阳热血妄行，血犯气分不归经，血病及腑渗浊道，伤于脏者溢出清，热犯阳络上吐衄，
热侵阴络下失红，又有努劳成血病，血止仍嗽势多凶。
【注】凡失血之证，阳盛乘阴，则血为热迫，不能安于脉中，犯于气分，妄行不能归
入经脉也。若血病伤及于腑者，则血渗入肠胃之浊道，上行于咽，出而为吐为衄；下从
二便而出，为便为尿也。若血病伤及于脏者，则溢出于胸中之清道，上从喉出，而兼咳嗽；
下从精窍而出，为尿血也。夫血藏于脏内，行于脉中，流于躯壳之内，不可得而见也。非
损伤不能为病，而损之之因有三∶一曰热伤阳络，腑病也；热伤阴络，脏病也，宜以清
热为主。一曰努伤，宜以破逐为主。一曰劳伤，宜以理损为主。若日久血止，而咳嗽不
休者，主必死之证，故势多凶也。
衄血之候鼻干燥，身热不渴苦头疼，失表分汗麻桂治，内热犀角泻心清。
【注】衄血者，鼻中出血也。其候鼻中干
燥，身热不渴，苦头痛，是热伤阳络也。有因伤寒失汗衄血者，乃热郁于营。其身无汗，
宜以麻黄汤汗之；身有汗者，宜以桂枝汤解之，设无表病，因内热而衄者，宜以犀角地
黄汤清之。热盛者，四物三黄泻心汤泻之。外俱用发灰散，或黑栀子未吹鼻，其衄自止。
麻黄汤
麻黄 杏仁（炒去皮尖） 桂枝 甘草（生）
引用生姜，水煎服。
【方歌】伤寒失表营郁热，身热无汗血妄行，须用麻黄汤调治，桂枝麻黄杏草同。
桂枝汤
桂枝 芍药 甘草（炙） 生姜 大枣
水煎服。
犀角地黄汤
牡丹皮 白芍药 犀角 生地黄
水煎服，便硬者加川大黄。
【方歌】犀角地黄汤，治衄效非常，丹皮芍犀地，便秘加大黄。
四物三黄泻心汤
川芎 当归（酒洗） 生地黄 赤芍药 黄芩 黄连 川大黄（酒洗）
水煎服。
【方歌】四物三黄泻心汤，热盛吐衄功最良，芎归生地赤芍药，黄芩黄连川大黄。
Yin invading Yang causes blood heat and reckless movement; blood invades the Qi level and fails to return to the meridians. If blood disease affects the Fu organs, it seeps into the turbid pathways of excretion; if it injures the Zang organs, it overflows from the clear orifices. Heat attacking the Yang collaterals leads to upper hematemesis and epistaxis; heat invading the Yin collaterals leads to lower hematochezia and hematuria. There are also blood diseases caused by strain and labor; if coughing persists after bleeding stops, the prognosis is often ominous.
[Note] In all cases of hemorrhage, if Yang excess invades Yin, blood is forced by heat and cannot remain within the vessels, invading the Qi level and moving recklessly without returning to the meridians. If blood disease injures the Fu organs, blood seeps into the turbid pathways of the intestines and stomach, ascending through the pharynx to be vomited as hematemesis or epistaxis; descending through the bowels and bladder to appear as hematochezia or hematuria. If blood disease injures the Zang organs, blood overflows from the clear pathways of the chest, ascending through the larynx accompanied by coughing; descending through the urethra to appear as hematuria. Blood is stored within the Zang organs, circulates within the vessels, and flows within the body shell, normally invisible. Disease does not occur without injury, and there are three causes of injury: first, heat injuring the Yang collaterals (Fu organ disease) and heat injuring the Yin collaterals (Zang organ disease), both should be treated primarily with clearing heat; second, injury from strain, which should be treated primarily with breaking stasis and expelling blood; third, injury from fatigue/labor, which should be treated primarily with regulating deficiency. If, after a long duration, bleeding stops but coughing continues, it indicates a fatal condition, hence the prognosis is often ominous.
The signs of epistaxis include dry nasal passages, fever without thirst, and distressing headache. If due to unresolved exterior syndrome requiring sweating, treat with Mahuang Tang (Ephedra Decoction) or Guizhi Tang (Cinnamon Twig Decoction); if due to internal heat, clear with Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction).
[Note] Epistaxis refers to bleeding from the nose. Its signs include dry nasal passages, fever without thirst, and distressing headache, indicating heat injuring the Yang collaterals. Some cases of epistaxis arise from failure to sweat in Shanghan (Cold Damage), where heat is constrained in the Ying (Nutritive) level. If the body has no sweat, use Mahuang Tang (Ephedra Decoction) to induce sweating; if the body has sweat, use Guizhi Tang (Cinnamon Twig Decoction) to resolve the exterior. If there is no exterior syndrome but epistaxis occurs due to internal heat, use Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction) to clear heat. If heat is excessive, use Siwu Sanhuang Xiexin Tang (Four Substances and Three Yellows Xiexin Decoction) to purge fire. Externally, apply Fahuisan (Hair Ash Powder) or black Zhizi powder insufflated into the nose, and the bleeding will stop naturally.
Mahuang Tang (Ephedra Decoction)
Ingredients: Ephedrae Herba (Mahuang, 麻黄), Armeniacae Semen Amarum (Xingren, 杏仁 - stir-fried, skin and tip removed), Cinnamomi Ramulus (Guizhi, 桂枝), Glycyrrhizae Radix et Rhizoma (Gancao, 甘草 - raw).
Usage: Add Zingiberis Rhizoma Recens (Shengjiang, 生姜) as a guide, decoct in water and take orally.
[Formula Song] Cold damage with failed sweating leads to Ying-level constraint and heat; fever and anhidrosis cause blood to move recklessly. One must use Mahuang Tang for treatment, composed of Cinnamon Twig, Ephedra, Apricot Seed, and Licorice.
Guizhi Tang (Cinnamon Twig Decoction)
Ingredients: Cinnamomi Ramulus (Guizhi, 桂枝), Paeoniae Radix (Shaoyao, 芍药), Glycyrrhizae Radix et Rhizoma (Gancao, 甘草 - honey-fried), Zingiberis Rhizoma Recens (Shengjiang, 生姜), Jujubae Fructus (Dazao, 大枣).
Usage: Decoct in water and take orally.
Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction)
Ingredients: Moutan Cortex (Mudanpi, 牡丹皮), Paeoniae Radix Alba (Baishaoyao, 白芍药), Rhinocerotis Cornu (Xijiao, 犀角), Rehmanniae Radix Preparata (Shengdihuang, 生地黄).
Usage: Decoct in water and take orally. If stool is hard, add Rhei Radix et Rhizoma (Chuan Dahuang, 川大黄).
[Formula Song] Xijiao Dihuang Tang is extremely effective for treating epistaxis, composed of Moutan Bark, Paeonia, Rhinoceros Horn, and Rehmannia; add Rheum for constipation.
Siwu Sanhuang Xiexin Tang (Four Substances and Three Yellows Xiexin Decoction)
Ingredients: Chuanxiong Rhizoma (Chuanxiong, 川芎), Angelicae Sinensis Radix (Danggui, 当归 - wine-washed), Rehmanniae Radix Preparata (Shengdihuang, 生地黄), Paeoniae Radix Rubra (Chishaoyao, 赤芍药), Scutellariae Radix (Huangqin, 黄芩), Coptidis Rhizoma (Huanglian, 黄连), Rhei Radix et Rhizoma (Chuan Dahuang, 川大黄 - wine-washed).
Usage: Decoct in water and take orally.
[Formula Song] Siwu Sanhuang Xiexin Tang is most excellent for treating hematemesis and epistaxis due to excessive heat, composed of Chuanxiong, Angelica, Rehmannia, Red Peony, Scutellaria, Coptis, and Rheum.