失血之症有四∶从齿失者，曰齿衄；从鼻失者，曰鼻衄；从咽失者，曰呕血；从喉失者，曰咳血、曰咯血
、曰吐血、曰唾血。失血则一，而轻重攸分。最轻者齿衄，足阳明胃脉循鼻入上齿，手阳明脉上颈贯颊入下齿，
二经热盛，其循经之血从齿溢出。血路一通，即无热，亦时常而来，于体无伤，不必以药治者也。稍轻者鼻
衄。凡经之上于头者皆下通于鼻，少阳之脉上抵头角，太阳之脉上额交颠，阳明之脉上至额颅。其血之循于
经者，随气周流，走而不守，三经为热所逼，血即从鼻而漏。以童便引热下行，茅根清胃降火，其血立止。至
于漏血过多而无休者，则不责之血热，而责之气虚。有形血，一时所不能滋；几希之气，速当挽回，急用参
补气以督血（经验方∶黄 一两、秦归三钱，姜枣引），补气以摄血，补气以生血。虽气息奄奄，亦可回生。
彼伤寒鼻衄，名曰红汗，热随血解，不必止血，亦不必再发汗；瘟疫鼻衄，名曰外溃，毒从血减，不必止血，亦
不必再议下。经络分明，见其症，即可以用其药也。稍重者呕血，即在胃腑矣。贮积日久，郁而上呕，多则盈
盆盈碗，聚则成块成堆。或一月一
呕，或间月一呕，或周年一呕。未呕之先，郁闷难安；已呕之后，神清气爽，但得血路通利，有呕至耄耋而无
伤者。以恐血阻吸门（急备方∶用纸捻刺鼻中，得嚏则通），登时至毙，方书积案，从未有发明其义者。盖胃
为五脏六腑之海，血易为之聚，人而饮食煎熬，停留瘀血，结成窠臼，久则相生相养，习以为常，如蚁之有穴，
鱼之有渊，生生不已。补之，愈足以滋其党；凉之，徒足以塞其路。辗转图维，惟三七、郁金，以破负固之
城；淮膝、大黄，以开下行之路（悬拟方∶三七、郁金、牛膝、大黄、归尾、桃仁、枳实、炼蜜为丸）。扫除
而荡涤之，庶有瘳焉。常见山居之民，采草药以治血，遇是症得愈者居多，草药之性，无非破血之品，有明征
矣。最重者吐血、咳血、咯血、唾血。致病之舋，原不一端；发病之源，总归五脏。脏者，藏也，所以藏其血
以养神、养魂、养魄、养意、养精与志也。心不主血，则神为之消散，脾不统血，则意为之惝恍，肝肺不归血，
则魂魄为之飘荡，肾不贮血，则精志为之梏亡。一滴之血，性命随之，全凭脉息以决吉凶。脉而虚弱，火犹
未发，归脾汤（人参、白术、茯苓、枣仁、龙眼肉、黄 、秦归、远志、木香、炙草、姜枣引）、养营汤（人
参、白术、黄 、炙草、陈皮、肉桂、秦归、熟地、五味、茯苓、远志、酒芍、姜枣引），俱能奏效；脉而洪
数则内火炽矣，火愈炽而血愈亡，血愈亡而阴愈虚，故曰阳邪之甚，害必归阴。当此之时，寒凉适足以伐五脏
之生气，温补又足以伤两肾之真阴，惟以寒滋其阴而养其阳（同痨伤论），血或归其位耳。又有一种，五脏为
内寒所侵，血不安位而妄行者，脉虚而迟，非附子、干姜，不足以祛其寒而温其经（经验方∶附片、干姜、黄
、白术、秦归、炙草、建元、南枣引），
此百中仅见一二者。至于外寒犯乎五脏，扰血逆上者。脉浮而紧，惟麻黄人参芍药汤（桂枝五分，麻黄、黄
、甘草、白芍一钱，人参、麦冬三钱，五味五粒，当归五分），可以攻其寒而安其血。此亦血症之常事，甚无
足怪。所以五脏之血，必诊脉而后能决也。综而计之，譬之军伍，齿衄、鼻衄，巡哨之士卒也；呕血，护卫之
士卒也；咳、吐、咯、唾之血，则守营之士卒也。巡哨之士卒可失，即护卫之士卒可失，而守营之士卒，断不
可失者也。经四十载之推求，而血症了解，阅千百人之性命，而血路敢详。
（司马刘芹藻，忽患失血，气喘，脉虚而迟，重用附子、干姜，黄 ，立愈。由是留心医学，讲解《灵》
、《素》、《难经》。）
失血这一类病症主要有四种：从牙齿出血的，称为齿衄；从鼻子出血的，称为鼻衄；从咽喉部呕出的，称为呕血；从喉咙咳出或吐出的，称为咳血、咯血、吐血、唾血。虽然都是失血，但轻重程度截然不同。
最轻微的是齿衄。足阳明胃经的经脉循行经过鼻子进入上齿，手阳明大肠经的经脉上行颈部穿过面颊进入下齿。如果这两条经络热邪炽盛，循经运行的血液就会从牙齿溢出。既然血路已经通畅，即使没有热邪，也会时常发生，这对身体没有太大伤害，不需要用药治疗。
稍微轻一点的是鼻衄。凡是经脉上行到头部的，都向下连通到鼻子。少阳胆经的经脉上行抵住头角，太阳膀胱经的经脉上行至额头交于头顶，阳明胃经的经脉上行至额颅。血液在经脉中随气周流运行，走而不守，如果这三条经络被热邪逼迫，血液就会从鼻子漏出。可以用童便（童子尿）引导热邪下行，用白茅根清胃降火，血液立刻就能止住。至于漏血过多且不停止的情况，就不归咎于血热，而应归咎于气虚。有形的血液一时难以滋补，几希之气速当挽回，急需用人参补气以统摄血液（经验方：黄芪一两、当归三钱，用生姜和大枣做药引），通过补气来摄血，通过补气来生血。即使病人气息奄奄，也可以起死回生。
那些患伤寒引起的鼻衄，名叫“红汗”，热邪随着血液排出而解除，不需要止血，也不需要再发汗；瘟疫引起的鼻衄，名叫“外溃”，毒邪随着血液减少而减轻，不需要止血，也不需要再讨论使用泻下法。经络分明，看到症状，就可以使用相应的药物。
稍微重一点的是呕血，病位就在胃腑。血液积聚日久，郁结而上逆呕吐，多的时候盈盆满碗，聚集成块成堆。或者一个月呕一次，或者隔月呕一次，或者一年呕一次。在没呕吐之前，感到郁闷难安；呕吐之后，神清气爽。只要血路通畅，有的人即使呕吐到八十岁高龄也没有受伤。之所以担心血液阻塞吸门（急备方：用纸捻刺激鼻孔，打出喷嚏则通路打开），导致当时就死亡，医书病例中从未有人阐明其中的道理。大概因为胃是五脏六腑的海，血液容易在此聚集，人饮食煎熬，停留形成瘀血，结成巢穴，久而久之相生相养，习以为常，就像蚂蚁有洞穴，鱼有深渊，生生不息。如果用补法，反而足以滋养其同类；如果用凉法，徒然足以堵塞其路径。辗转思考，只有用三七、郁金，来攻破顽固的城池；用怀牛膝、大黄，来开辟下行的道路（悬拟方：三七、郁金、牛膝、大黄、当归尾、桃仁、枳实、炼蜜为丸）。扫除并荡涤瘀血，才可能有痊愈的希望。常见山居百姓，采集草药治疗血证，遇到这种病症治愈的居多，草药的性质，无非是破血的品种，这是明显的证据。
最严重的是吐血、咳血、咯血、唾血。致病的起因，原本不止一端；发病的源头，总归五脏。脏，就是藏的意思，用来贮藏血液以养神、养魂、养魄、养意、养精与志。心如果不主司血液，神就会消散；脾如果不统摄血液，意就会恍惚；肝肺如果不使血液回归本位，魂魄就会飘荡；肾如果不贮存血液，精志就会困亡。一滴血关系到性命，全凭脉象来决断吉凶。
如果脉象虚弱，说明火邪尚未发作，归脾汤（人参、白术、茯苓、酸枣仁、龙眼肉、黄芪、当归、远志、木香、炙甘草，用生姜大枣做药引）、养营汤（人参、白术、黄芪、炙甘草、陈皮、肉桂、当归、熟地黄、五味子、茯苓、远志、酒白芍，用生姜大枣做药引），都能奏效；如果脉象洪数，说明内火炽盛了，火越炽盛血越亡失，血越亡失阴液越虚，所以说阳邪极甚，危害必然归于阴分。在这个时候，寒凉药足以砍伐五脏的生气，温补药又足以损伤两肾的真阴，只有用寒凉滋润阴液同时养护阳气（参考痨伤论），血液或许才能回归其位。
又有一种情况，五脏被内寒侵袭，血液不安于原位而妄行的，脉象虚而迟，不用附子、干姜，不足以祛除寒邪而温通经脉（经验方：附片、干姜、黄芪、白术、当归、炙甘草，建元、南枣做药引），这种情况百中仅见一两个。至于外寒侵犯五脏，扰乱血液使其逆上的，脉象浮而紧，只有麻黄人参芍药汤（桂枝五分，麻黄、黄芪、甘草、白芍各一钱，人参、麦冬各三钱，五味子五粒，当归五分），可以攻逐寒邪而安定血液。这也是血证的常事，没什么可奇怪的。所以五脏相关的血证，必须诊脉后才能决断。
综合起来计算，好比军队编制，齿衄、鼻衄，是巡哨的士卒；呕血，是护卫的士卒；咳、吐、咯、唾之血，则是守卫营垒的士卒。巡哨的士卒可以损失，即使是护卫的士卒也可以损失，但守卫营垒的士卒，绝对不可以损失。经过四十年的推求，对血证有了了解，阅看千百人的性命，才敢详细论述血路。
（司马刘芹藻，忽然患失血，气喘，脉象虚而迟，重用附子、干姜、黄芪，立刻痊愈。从此留心医学，讲解《灵枢》、《素问》、《难经》。）
There are four types of bleeding disorders: bleeding from the teeth is called Chi Nu (Tooth Bleeding); bleeding from the nose is called Bi Nu (Nosebleed); vomiting blood from the throat is called Ou Xue (Vomiting Blood); coughing or spitting blood from the larynx is called Ke Xue (Coughing Blood), Luo Xue (Spitting Blood), Tu Xue (Hematemesis), or Tuo Xue (Saliva with Blood). Although all involve blood loss, their severity varies significantly.
The mildest is Tooth Bleeding. The Foot-Yangming Stomach Meridian passes through the nose into the upper teeth, and the Hand-Yangming Large Intestine Meridian ascends the neck, passes through the cheek, and enters the lower teeth. If heat pathogen is excessive in these two meridians, blood circulating along them may overflow from the teeth. Since the blood pathway is open, even without heat pathogen, it may occur frequently; this causes little harm to the body and requires no medicinal treatment.
Slightly more severe is Nosebleed. All meridians ascending to the head connect downward to the nose. The Shaoyang Gallbladder Meridian ascends to the temple; the Taiyang Bladder Meridian ascends to the forehead and intersects at the vertex; the Yangming Stomach Meridian ascends to the frontal skull. Blood circulates within the meridians following Qi, moving freely without staying fixed. When forced by heat pathogen in these three meridians, blood leaks from the nose. Tongzi Bian (Child's Urine) can guide heat downward, and Bai Mao Gen (Rhizoma Imperatae) clears the stomach and descends fire, stopping the bleeding immediately. However, if bleeding is excessive and unceasing, the cause is not attributed to blood heat but to Qi deficiency. Solid blood cannot be replenished instantly, so vital Qi must be restored quickly. Urgently use Renshen (Radix Ginseng) to tonify Qi and control blood (Empirical Formula: Huangqi 30g, Danggui 9g, guided by Shengjiang and Dazao). Tonifying Qi controls blood, generates blood, and even if the patient is critically weak, recovery is possible.
In cases of Nosebleed due to Shanghan (Cold Damage), known as "Red Sweat," the heat resolves with the blood; hemostasis and diaphoresis are unnecessary. In plague-induced Nosebleed, known as "External Ulceration," toxins decrease with blood loss; hemostasis and purgation are unnecessary. With clear meridians and symptoms, appropriate herbs can be applied directly.
Slightly more severe is Vomiting Blood, located in the Wei Fu (Stomach Organ). Accumulated over time, stagnation leads to upward vomiting, filling basins and bowls, forming clumps. It may occur monthly, bi-monthly, or annually. Before vomiting, there is depression and discomfort; after vomiting, one feels refreshed. As long as the blood pathway remains patent, some may vomit blood until old age without injury. The danger lies in blood blocking Xi Men (the glottis/respiratory opening) (Emergency Method: stimulate the nasal mucosa with a paper twist to induce sneezing, thereby opening the passage), leading to sudden death. Medical texts rarely explain this mechanism. The Stomach is the sea of the five Zang and six Fu organs; blood easily accumulates here. Dietary retention forms stasis, creating nests that sustain themselves like ant hills or fish pools. Tonification nourishes the stasis; cooling merely blocks the pathway. Therefore, only Sanqi (Radix Notoginseng) and Yujin (Rhizoma Curcumae) can break the fortified city; Huai Nixi (Radix Achyranthis Bidentatae) and Dahuang (Radix et Rhizoma Rhei) can open the descending pathway (Proposed Formula: Sanqi, Yujin, Niuxi, Dahuang, Dangguiwei, Taoren, Zhishi, refined honey pills). Sweeping away and purging the stasis offers hope for cure. Mountain dwellers often use herbal remedies for blood disorders, achieving many cures, proving that these herbs possess blood-breaking properties.
The most severe are Hematemesis, Coughing Blood, Spitting Blood, and Saliva with Blood. Etiologies vary, but the source lies in the Five Zang organs. Zang organs store blood to nourish Shen (Spirit), Hun (Ethereal Soul), Po (Corporeal Soul), Yi (Intellect), Jing (Essence), and Zhi (Will). If the Heart does not govern blood, Shen dissipates; if the Spleen does not control blood, Yi becomes confused; if the Liver and Lung do not return blood to its proper position, Hun and Po wander; if the Kidney does not store blood, Jing and Zhi are destroyed. A single drop of blood relates to life and death; prognosis depends entirely on the pulse.
If the pulse is weak and deficient, indicating fire has not yet flared, Guipi Tang (Spleen-Restoring Decoction: Renshen, Baizhu, Fuling, Suanzaoren, Longyanrou, Huangqi, Danggui, Yuanzhi, Muxiang, Zhigancao, guided by Shengjiang and Dazao) and Yangying Tang (Nourishing Camp Decoction: Renshen, Baizhu, Huangqi, Zhigancao, Chenpi, Rougui, Danggui, Shudihuang, Wuweizi, Fuling, Yuanzhi, Jiubaishao, guided by Shengjiang and Dazao) are effective. If the pulse is surging and rapid, internal fire is blazing. The fiercer the fire, the greater the blood loss; the greater the blood loss, the more deficient the Yin. Thus, extreme Yang pathogenic factors inevitably damage Yin. At this stage, cold-natured herbs may destroy the vital energy of the Zang organs, while warm-tonic herbs may damage the true Yin of the Kidneys. One must use cold-natured herbs to nourish Yin while simultaneously supporting Yang (refer to Tuberculosis discussion), allowing blood to return to its proper position.
Another scenario involves internal cold invading the Zang organs, causing blood to act recklessly outside its normal position. The pulse is weak and slow. Without Fuzi (Lateral Root of Aconite) and Ganjiang (Dried Ginger), cold cannot be dispelled and meridians warmed (Empirical Formula: Fupian, Ganjiang, Huangqi, Baizhu, Danggui, Zhigancao, Jianyuan, Nanzao guided). This occurs in only one or two out of a hundred cases. If external cold invades the Zang organs, disturbing blood causing it to rebel upward, the pulse is floating and tight. Only Mahuang Renshen Shaoyao Tang (Ephedra, Ginseng, and Peony Decoction: Guizhi 1.5g, Mahuang, Huangqi, Gancao, Baishao 3g each, Renshen, Maidong 9g each, Wuweizi 5 berries, Danggui 1.5g) can attack the cold and stabilize the blood. This is a common occurrence in blood disorders and is not surprising. Therefore, blood disorders related to the Five Zang organs require pulse diagnosis for accurate decision-making.
In summary, consider the military analogy: Tooth Bleeding and Nosebleed are patrol soldiers; Vomiting Blood is guard soldiers; Coughing, Vomiting, Spitting, and Saliva-with-blood are camp-defending soldiers. Patrol soldiers may be lost, guard soldiers may be lost, but camp-defending soldiers must never be lost. After forty years of research and observing thousands of lives, I dare to detail the pathways of blood.
(Sima Liu Qinzao suddenly suffered from blood loss and asthma with a weak and slow pulse. Using heavy doses of Fuzi, Ganjiang, and Huangqi, he recovered immediately. Thereafter, he devoted himself to medicine, lecturing on the Ling Shu, Su Wen, and Nan Jing.)