尝思血之为物也。和调于五脏。洒成于六腑。其色属火。其形类水。内主于心。外行于营。循环上下。灌溉周
流。以应度数。以奉生身。故经曰。血气者。人之神。不可不谨养。若乃将息失宜。嗜欲过度。外感六淫之邪。内
动五脏之志。营卫不调。脏腑相胜。有过不及。病斯见焉。彼谓诸见血皆热证者。是知其属火。而不知其类
水。知其太过。而不知其不及也。析而论之。则出于九窍。曰九窍出血。出于小便曰尿血。曰血淋。出于大便。
曰肠风。曰血痔。从鼻出曰鼻衄。从舌出曰舌衄。从齿龈出曰齿衄。从汗孔出曰肌衄。因呕而出曰呕血。因
吐而出曰吐血。因咯而出曰咯血。因唾而出曰唾血。因咳而出曰咳血。因嗽而出曰嗽血。凡诸血证。所出
不同。所因亦异。而况有殴伤出血。跌仆出血者乎。况有月事逆行。伤寒误汗者乎。他如外科之疮疡出血。
女科之崩漏夺血。以及胎前产后。半产下痢。亦指不胜屈矣。故内经谓诸血皆属于心则可。丹溪谓诸见
血皆热证。则断断不可。且就血而论其形色。亦有可辨。如诸书谓精壮者。血轮多。故色浓而赤。虚弱者。血
轮少。故色淡而稀。阳证溢出鲜血。阴证下如豚肝。新血鲜红。旧血瘀黑。色之鲜紫浓浓者。为气盛。色之晦
暗无光者。为气衰。风证色青。寒证色暗。暑证色赤。湿证色如烟煤屋漏。便血浅褐色者已重。深褐色者尤
重。褐色变黑者极重。吐血带痰沫及粉红色者属于肺。正赤如朱漆光泽者。属于心包络。鲜紫浓浓者属
于脾。青紫稠浓。或带血缕。或有结块者属于肝。咯吐稀痰。中杂如珠。血无几。色不鲜者属于肾。成盘成盏。
多兼水谷痰涎者属于胃。若从大便出者。多属大小肠。从小便出者。多属膀胱肾。此皆因形色而分也。其
出于五官四体。又当因经络而分焉。故经曰。阳络伤。则血外溢。血外溢。则衄血。阴络伤。则血内溢。血内溢。
则后血。凡血证。阳证则身热多渴。阴证则身冷不渴。有潮热者重。无潮热者轻。上行多逆。下行多顺。若吐
出便凝。摸之不粘指者。为守脏之血。口鼻俱出如涌泉者。为心肺脉破。则皆不可治也。然予犹有说焉。如
吐血先鲜红而后凝紫。先多而后少。先疾而后徐者。其势渐减。先凝紫而后鲜红。先少而后多。先徐而后
疾者。其势渐增。亦皆可以相参也。若夫因气色而病异。因脉证而病异。又当合四诊而观之。此特粗举隅
焉。以明诸见血。非皆热证也。丹溪谓知其要者。可一言而终。言不可以若是其几也。何也。不知其要。斯害
也已。
我曾思考，血作为一种物质，在五脏中调和，在六腑中化生。它的性质属火，形态类似水。在内由心主宰，在外运行于营分，上下循环，灌溉全身，以符合生理节律，供养生命。所以医经说：“血气是人的精神所在，不可不谨慎调养。”如果起居调摄不当，欲望过度，外感六淫邪气，内伤五脏情志，导致营卫不调，脏腑相克，出现太过或不及的情况，疾病就会显现。那些认为所有出血症状都是热证的人，是只知道血属火的特性，而不知道它类水的特性；只知道血热太过的情况，而不知道血寒不及的情况。详细分析来说，从九窍出血的，称为九窍出血；从小便而出的，称为尿血、血淋；从大便而出的，称为肠风、血痔；从鼻而出的，称为鼻衄；从舌而出的，称为舌衄；从齿龈而出的，称为齿衄；从汗孔而出的，称为肌衄；因呕吐而出的，称为呕血；因剧烈吐出而出的，称为吐血；因咯出而出的，称为咯血；因唾出而出的，称为唾血；因咳嗽而出的，称为咳血；因嗽出而出的，称为嗽血。大凡各种血证，出血部位不同，病因也各异，更何况有殴打受伤出血、跌打损伤出血的呢？何况有月经逆行、伤寒误用发汗法导致的出血呢？其他如外科疮疡出血，妇科崩漏失血，以及产前产后、小产下痢等，也数不胜数。所以《内经》说“诸血皆属于心”是可以的，但朱丹溪说“所有出血症状都是热证”，则是绝对错误的。
而且就血液本身来辨别其颜色和形态，也有可分辨之处。如各书所说，精气壮盛的人，血轮多，所以血色浓赤；体虚的人，血轮少，所以血色淡稀。阳证溢出的鲜血，阴证排出的血像猪肝一样。新血鲜红，旧血瘀黑。颜色鲜紫浓郁的，属于气盛；颜色晦暗无光的，属于气衰。风证血色青，寒证血色暗，暑证血色赤，湿证血色如烟煤屋漏状。便血呈浅褐色的已经严重，深褐色的尤其严重，褐色变黑的极重。吐血带有痰沫及粉红色的属于肺，正红色如朱漆光泽的属于心包络，鲜紫浓郁的属于脾，青紫稠浓或带血丝、或有血块的属于肝，咯吐稀痰中夹杂如珠状、血量不多、颜色不鲜的属于肾，成盘成盏状、多兼有水谷痰涎的属于胃。若从大便而出的，多属大小肠；从小便而出的，多属膀胱和肾。这些都是根据颜色和形态来区分的。而出于五官四体的，又应当根据经络来区分。所以医经说：“阳络受伤，则血外溢，血外溢则发生衄血；阴络受伤，则血内溢，血内溢则发生便血。”大凡血证，阳证则身体发热、多口渴，阴证则身体寒冷、不口渴。有潮热的病情重，无潮热的病情轻。血上行多为逆证，下行多为顺证。如果吐出的血凝固，摸起来不粘手指的，是守脏之血（未伤及脏腑）；口鼻同时出血如涌泉状的，是心肺脉络破裂，都不可治。
然而我还有话说。如吐血先鲜红后凝紫，先多后少，先急后缓的，病情逐渐减轻；先凝紫后鲜红，先少后多，先缓后急的，病情逐渐加重。这些都可以参考判断。至于因气色不同而病异，因脉象症状不同而病异，又应当结合望、闻、问、切四诊来观察。这里只是粗略列举一二，以说明所有出血症状并非都是热证。丹溪说“知道要领的人，可以一言终结”，话不可以说得这么简略。为什么呢？因为不知道要领，危害就大了啊。
I have pondered that blood, as a substance, is harmonized within the Five Viscera (Wu Zang) and transformed in the Six Bowels (Liu Fu). Its nature belongs to Fire, while its form resembles Water. Internally, it is governed by the Heart; externally, it circulates within the Ying (Nutritive) level. It cycles up and down, irrigating the entire body in accordance with physiological rhythms to nourish life. Therefore, the medical classics state: "Blood and Qi are the spirit of humans; they must not be neglected in nurturing." If daily regimen is improper, desires are excessive, external pathogens of the Six Evils invade, or internal emotions disturb the Five Viscera, leading to disharmony between Ying and Wei, mutual overacting among Zang-Fu organs, and conditions of excess or deficiency, diseases will manifest. Those who claim that all hemorrhagic symptoms are Heat syndromes only know that blood belongs to Fire but ignore that it resembles Water; they recognize cases of excess (Heat) but fail to understand cases of deficiency (Cold). Analyzing in detail: bleeding from the nine orifices is called bleeding from the nine orifices; bleeding from urination is called hematuria or bloody strangury; bleeding from defecation is called intestinal wind or bloody hemorrhoids; bleeding from the nose is called epistaxis; bleeding from the tongue is called lingual bleeding; bleeding from the gums is called gingival bleeding; bleeding from sweat pores is called cutaneous bleeding; vomiting blood is called emesis of blood; forceful spitting out of blood is called hematemesis; coughing up blood is called hemoptysis; spitting saliva with blood is called salivary bleeding; coughing up blood is called cough-blood; clearing throat with blood is called sputum-blood. Generally, various blood disorders differ in site of origin and etiology. Furthermore, what about bleeding due to blows or falls? What about retrograde menstruation or misapplied diaphoresis in Cold Damage (Shang Han)? Other examples include bleeding from surgical sores, gynecological metrorrhagia and metrostaxis causing blood loss, as well as pre- and post-partum conditions, miscarriage with dysentery, which are too numerous to mention. Thus, it is acceptable for the *Nei Jing* to state "all blood disorders belong to the Heart," but Zhu Danxi's assertion that "all visible blood disorders are Heat syndromes" is absolutely incorrect.
Moreover, observing the color and morphology of blood allows for differentiation. As texts describe, individuals with robust essence have more "blood wheels" (capillary networks), resulting in dark red, concentrated blood; those with weakness have fewer, resulting in pale, thin blood. In Yang syndromes, fresh bright red blood is discharged; in Yin syndromes, blood resembles pig liver. Fresh blood is bright red; old blood is dark and stasis-like. Bright purple and rich color indicates abundant Qi; dull and lusterless color indicates deficient Qi. Wind syndromes show blue-green color; Cold syndromes show dark color; Summerheat syndromes show red color; Dampness syndromes show color like soot or leaking roof tiles. Stool blood that is light brown is already severe; dark brown is particularly severe; turning black is extremely severe. Hematemesis mixed with frothy sputum and pink color belongs to the Lung; pure red like vermilion lacquer with gloss belongs to the Pericardium; bright purple and rich belongs to the Spleen; dark purple, thick, possibly with streaks or clots belongs to the Liver; spitting thin sputum mixed with pearl-like particles, with little blood and dull color belongs to the Kidney; blood forming plates or cups, mixed with food residue and phlegm-drool belongs to the Stomach. Bleeding from stool mostly involves the Large and Small Intestines; bleeding from urine mostly involves the Bladder and Kidneys. These distinctions are based on color and shape. Bleeding from the five sense organs and four limbs should be differentiated according to meridians. Hence, the classics state: "Injury to Yang collaterals causes blood to overflow outward, leading to nasal bleeding; injury to Yin collaterals causes blood to overflow inward, leading to lower bodily bleeding." Generally, in blood disorders, Yang syndromes present with fever and thirst; Yin syndromes present with cold limbs and no thirst. Cases with tidal fever are severe; those without are mild. Upward flow is often adverse; downward flow is often favorable. If vomited blood coagulates and feels non-sticky to touch, it is blood retained within the viscera (not damaging them); if blood spurts from both mouth and nose like a fountain, it indicates rupture of Heart and Lung vessels, which is incurable.
However, I have further observations. For instance, hematemesis that starts bright red then turns dark purple, starts heavy then light, starts rapid then slow, indicates decreasing severity. Conversely, starting dark purple then bright red, starting light then heavy, starting slow then rapid, indicates increasing severity. These can be referenced together. Regarding variations due to complexion or pulse/symptoms, one must integrate the Four Diagnostic Methods (Inspection, Auscultation-Olfaction, Inquiry, Palpation). This is merely a rough outline to clarify that not all hemorrhagic symptoms are Heat syndromes. Danxi said, "He who knows the essentials can summarize in one word," but such brevity is misleading. Why? Because ignorance of the essentials leads to harm.