血从鼻出，谓之衄。衄之出也，由阳明经脉之气，不循胃络而横通周遍，致悍热之气伤其荣血，遂迫血妄
行而为衄。若伤寒阳热过盛，络脉寒凝。荣卫不调，身发热者，得衄则阴阳和而热气平，其病可愈，故俗称鼻
衄为红汗也。其有不病伤寒，时出衄者，乃阳明热气有余，不循经下行，反上逆而伤其络脉之所致也；衄出，
则阳明亢热之气亦平，故不药亦愈，此衄至轻者也。又有阳明经脉虚寒，其人秉质素弱，内则耗其精血，外则
劳其形体，衄大出不止，用凉血滋阴药，其衄反甚者，乃阳明阳气失职，必用人参、附子，补气以摄血，助阳以救
阴，其血方止，此衄之至重者也。欲辨衄之重轻，须察衄之冷热。衄出觉热者，乃阳明络脉之血，轻者也，治
宜凉血滋阴；衄出觉冷者，乃阳明经脉之血，重者也，治当温经助阳。夫衄血之病，虽属平常，若出而不止，阴
阳离脱，亦有死者。临病施治，常须识此，不可忽也！
便血，俗名肠红，血从大便出也。或在粪前，或在粪后，但粪从肠内出，血从肠外出。肠外出者，从肛门
之宗眼出也。此胞中血海之血，不从冲脉而上行外达，反渗漏于下，用力大便，血随出矣。此病初起，人多不
觉；及至觉时，而身体如常，亦玩忽不治，即或治之，无非凉血清火，暂止复发，数年之后，身体疲倦，恣投药
饵，总不除根，遂成终身之痼疾矣。痼疾虽成，不致殒
命。其治法总宜温补，不宜凉泻；温暖则血循经脉，补益则气能统血。初便血时，治得其宜，亦可全愈；若因
循时日，久则不能愈矣。
血液从鼻腔流出，称为衄血。衄血的发生，是由于阳明经脉之气，不沿着胃络运行而横向通达周身，导致刚悍的热气损伤了营血，从而逼迫血液妄行而出而形成衄血。如果是伤寒病中阳热过盛，导致络脉寒凝（注：此处原文逻辑似有矛盾或特指寒包火/格拒，依文意直译），营卫不调，身体发热的人，通过衄血可以使阴阳调和、热气平息，疾病即可痊愈，所以俗称鼻衄为“红汗”。那些没有患伤寒病，时常出现衄血的人，是阳明热气有余，不顺着经络下行，反而上逆损伤了络脉所致；衄血流出后，阳明亢盛的热气也随之平息，所以不吃药也能痊愈，这是最轻的衄血。又有阳明经脉虚寒的人，其体质素来虚弱，内部耗损精血，外部劳损形体，导致大量衄血不止，如果使用凉血滋阴的药物，衄血反而加重，这是因为阳明阳气失职，必须用人参、附子，补气以摄血，助阳以救阴，血液才能停止，这是最重的衄血。想要辨别衄血的轻重，必须观察衄血时的冷热感觉。衄血时感觉热的，是阳明络脉的血，属于轻症，治疗应当凉血滋阴；衄血时感觉冷的，是阳明经脉的血，属于重症，治疗应当温经助阳。衄血这一病症，虽然平常，但如果出血不止，导致阴阳离决脱失，也有死亡的危险。临证施治时，常常需要知晓这一点，不可疏忽！
便血，俗称肠红，是指血液随大便排出。有的在粪便之前，有的在粪便之后，但粪是从肠道内排出，血是从肠道外排出。从肠道外排出的血，是从肛门的直肠末端（宗眼）流出的。这是由于胞宫中的血海之血，不顺着冲脉向上行并外达，反而渗漏于下，用力排便时，血液随之而出。此病初起时，人们往往没有察觉；等到发觉时，身体如常，也轻视不治疗，即使治疗，无非是用凉血清火的药物，暂时止住后又复发，数年之后，身体疲倦，随意投药，始终不能除根，于是成为终身的顽固疾病。顽固疾病虽然形成，但不致危及生命。其治疗方法总宜温补，不宜凉泻；温暖则血液循行于经脉，补益则气能统摄血液。初发便血时，治疗得当，也可以完全治愈；如果拖延时日，久了就不能治愈了。
Blood flowing from the nose is termed *Bi Xue* (Nosebleed). The occurrence of *Bi Xue* arises because the Qi of the Yangming Meridian does not follow the Stomach collaterals but instead spreads horizontally throughout the body, causing the fierce-heat Qi to damage the Ying Blood (Nutritive Blood), thereby forcing the blood to move recklessly and resulting in nosebleed. In cases of Cold Damage (*Shanghan*) where Yang-heat is excessive, leading to cold coagulation in the collaterals and disharmony of Ying and Wei (Defensive and Nutritive) levels, if the body is feverish, the occurrence of nosebleed allows Yin and Yang to harmonize and heat to subside, thus curing the disease; hence, it is commonly called "red sweat." For those who do not suffer from Cold Damage but experience frequent nosebleeds, it is due to excess heat in the Yangming channel that fails to descend along the meridian and instead reverses upward, damaging the collateral vessels; once the bleeding stops, the hyperactive heat of Yangming also subsides, so recovery occurs without medication, representing the mildest form of nosebleed. Conversely, individuals with deficiency-cold of the Yangming meridian, whose constitutions are inherently weak, having internally depleted their Essence and Blood and externally overtaxed their physical form, may suffer from profuse, unceasing nosebleed. If cooling-blood and yin-nourishing herbs are used, the bleeding worsens; this indicates failure of Yang Qi in the Yangming channel, requiring Ren Shen (Ginseng Root) and Fu Zi (Aconite Lateral Root) to tonify Qi to control blood and assist Yang to rescue Yin, after which the bleeding ceases—this represents the most severe form of nosebleed. To distinguish the severity of nosebleed, one must observe whether the blood feels hot or cold upon exit. Nosebleed accompanied by a sensation of heat involves blood from the Yangming collaterals and is mild, treated by cooling blood and nourishing Yin. Nosebleed accompanied by a sensation of cold involves blood from the Yangming meridian and is severe, treated by warming the meridians and assisting Yang. Although nosebleed is a common ailment, if bleeding continues uncontrollably leading to the separation and collapse of Yin and Yang, death may occur. Clinicians must be aware of this when prescribing treatment and must not neglect it.
Hematochezia (blood in stool), commonly known as "Intestinal Red," refers to blood expelled during defecation. It may appear before or after the feces, but while feces originate from within the intestines, blood originates from outside the intestinal lumen. This external blood flows from the rectal ampulla (Zong Yan) at the anus. It results from blood in the Sea of Blood (located in the uterus/lower abdomen) failing to ascend via the Chong Mai (Penetrating Vessel) and reach the exterior, instead leaking downward; upon straining during defecation, the blood is expelled. Initially, patients often do not notice this condition; when they do, their physical constitution may seem normal, leading them to ignore it. Even if treated, remedies typically consist only of cooling-blood and clearing-fire prescriptions that provide temporary relief followed by recurrence. Years later, fatigue sets in, and indiscriminate use of medications fails to eradicate the root cause, resulting in a lifelong chronic illness. Although chronic, this condition is not immediately fatal. The general treatment principle should be warming and tonifying, rather than cooling and purging; warmth ensures blood follows the meridians, and tonification enables Qi to control blood. If treated appropriately at the onset, complete recovery is possible; however, if time is allowed to pass, cure becomes difficult.