血症应分为三等，衄、唾、吐、呕为上部，血结胸为中部，蓄血下焦为下部。夫血何以能蓄也？
吴氏曰∶病在太阳，当汗不汗，则瘀血在里，必血结也。《活人》云∶失汗而热蓄在里，热化为
血，其人善忘而如狂，血上逆则善忘，血下蓄则内急。吴又可曰∶瘟疫失下，邪热久羁不泄，血为
热搏，留于经络，败为紫血，溢于肠胃，腐为黑血，便色如漆，大便反易，合此三说，而蓄血之义
始尽。盖病在太阳失汗，热蕴于中，血为热所抟，始流经络，继溢肠胃，则当下矣。斯时又失于下，
邪热久羁不泄，瘀于下焦，故少腹 满急胀，皮见青紫筋，则蓄血之症成矣。其见症则有喜忘，如狂
发狂，小便自利，□□大便色黑，谵妄燥渴，脉沉实结，皆蓄血之候。
医者诊视，盒饭揣其少腹 满而痛，即问其小便。若小便不利，是津液留结，可利小便；（此层倍。）
若小便自利者，即是蓄血矣。若太阳病，有热结膀胱（太阳本经。）而如狂者，症之轻者也，宜桃
仁承气汤。（此层又倍。）若阳明病，有蓄血而喜忘者，病之甚者也。抵当汤难用，可代以承气之类，
加桃仁、红花、归尾等破血之物，或兼虚者，以玉烛散之类下之，则蓄血去而病痊矣。
上所言者，道其常也。余有一孙，名河，方十四五岁。感瘟疫二十余日不解，诊其脉，空虚而
弱，不任寻按，亦并无喜忘如狂等症，但终日昏睡不清醒，按其腹，虽觉微痛，亦无 满急胀等候，
医有议补者，余力持其不可，伊芳时余方料理儿病，未暇及孙，亦未服药，静候数日，突欲大便，随
下紫血数斗，顿然清醒，此时方知其为蓄血。若当时一用补剂，则立毙矣。足见治瘟疫者，只知
其常，而不知其变，犹作文看书之死于句下也。可不慎哉！笔之以俟高明者。
血症应当分为上、中、下三等：鼻衄、唾血、吐血、呕血属于上部；血结胸属于中部；蓄血在下焦属于下部。那么，血液为什么能够蓄积呢？
吴氏说：病在太阳经，应当发汗却未发汗，导致瘀血停留在体内，必然形成血结。《活人书》中说：因失于发汗而热邪蓄积在体内，热邪煎熬血液，患者容易健忘且神情如狂，血液上逆则导致健忘，血液下蓄则导致腹部内部拘急。吴又可说：瘟疫病若失于攻下，邪热长期滞留无法排泄，血液被热邪搏结，留滞在经络中，败坏成为紫黑色的血，溢出到肠胃中，腐败成为黑血，大便颜色像漆一样黑，但大便反而容易排出。综合这三种说法，蓄血的含义才算穷尽。大概是因为病在太阳经时失于发汗，热邪蕴结在体内，血液被热邪搏结，开始流注于经络，继而溢入肠胃，此时应当使用下法。如果此时又失于攻下，邪热长期滞留无法排泄，瘀滞在下焦，所以少腹部胀满拘急疼痛，皮肤出现青紫色的筋脉，蓄血的病症就形成了。其临床表现有喜欢健忘、如狂或发狂、小便自利、大便色黑、谵语妄言、烦躁口渴、脉象沉实或结代，这些都是蓄血的征候。
医生诊察时，应当揣摸患者少腹部是否胀满疼痛，随即询问其小便情况。如果小便不利，这是津液停留结聚，可以使用利小便的方法治疗。（这一层需要加倍注意。）如果小便自利的，就是蓄血证了。如果是太阳病，有热邪结于膀胱（太阳本经），并且出现如狂症状的，是病情较轻的，适宜用桃仁承气汤。（这一层更需要加倍注意。）如果是阳明病，有蓄血并且出现喜忘症状的，是病情较重的。抵当汤难以使用，可以用承气汤类方剂代替，加入桃仁、红花、当归尾等破血药物，或者兼有虚证的，用玉烛散之类攻下，这样蓄血去除而病痊愈。
上面所说的是常理。我有个孙子，名叫河，年龄十四五岁。感染瘟疫二十多天没有解除，诊察他的脉搏，空虚而弱，不耐受重按，也没有喜欢健忘、如狂等症状，只是整天昏睡不清醒，按压他的腹部，虽然觉得微痛，也没有胀满拘急疼痛等表现。有的医生建议用补法，我极力坚持认为不可。当时我正在照料儿子的病，没空顾及孙子，他也没有服药，静静等待了几天，突然想大便，随即排出了几斗紫黑色的血，顿时清醒过来，这时才知道是蓄血证。如果当时使用补剂，就会立即死亡。足以看出治疗瘟疫的人，只知道常理而不知道变化，就像写文章看书死在句读之下一样。能不谨慎吗！记录下来以等待高明的人指正。
Hemorrhagic diseases should be divided into three levels: epistaxis (nosebleed), hemoptysis (blood in saliva), hematemesis (vomiting blood), and vomiting belong to the upper level; blood binding in the chest belongs to the middle level; blood accumulation in the lower jiao (lower burner) belongs to the lower level. How, then, can blood accumulate?
Wu said: When the disease is in the Taiyang meridian (Taiyang channel syndrome), if sweating should have been induced but was not, stasis of blood remains inside, leading inevitably to blood binding. The *Huoren* (Book for Saving People) states: If sweating is missed and heat accumulates internally, the heat transforms into blood; the patient suffers from forgetfulness and behaves like a madman. When blood reverses upward, it causes forgetfulness; when blood accumulates downward, it causes internal urgency. Wu Youke stated: In plague diseases, if purgation is missed, pathogenic heat lingers for a long time without being discharged. Blood is constrained by heat, remaining in the meridians, deteriorating into purple-black blood, overflowing into the intestines and stomach, rotting into black blood. The stool color is like lacquer, yet defecation is surprisingly easy. Combining these three theories, the meaning of blood accumulation is fully elucidated. Generally, when the disease is in the Taiyang meridian and sweating is missed, heat is trapped inside. Blood is constrained by heat, first flowing into the meridians, then overflowing into the intestines and stomach; at this point, purgation should be employed. If purgation is again missed at this time, pathogenic heat lingers for a long time without discharge, stasis occurs in the lower jiao, causing fullness, urgency, and distension in the lower abdomen, with blue-purple veins visible on the skin, thus forming the syndrome of blood accumulation. Its manifestations include forgetfulness, behaving like a madman or actual madness, free urination, dark-colored stools, delirium, dryness, thirst, and a deep, solid, or knotted pulse; all are signs of blood accumulation.
When physicians examine patients, they should palpate whether the lower abdomen is full and painful, and immediately ask about urination. If urination is difficult, it indicates retention and binding of body fluids, and diuretics may be used. (This aspect requires double attention.) If urination is free, it is blood accumulation. If it is a Taiyang disease with heat binding in the Bladder (the primary meridian of Taiyang) accompanied by behaviors resembling madness, it is a mild case, suitable for treatment with Tao Ren Cheng Qi Tang (Peach Kernel Decoction to Order the Qi). (This aspect requires even greater attention.) If it is a Yangming disease with blood accumulation accompanied by forgetfulness, it is a severe case. Di Dang Tang (Wait-and-See Decoction) is difficult to use; one may substitute it with formulas similar to Cheng Qi Tang, adding blood-breaking herbs such as Tao Ren (Peach Kernel), Hong Hua (Safflower), and Gui Wei (Tail of Angelica Sinensis). Or, if there is concomitant deficiency, one may use Yu Zhu San (Jade Candle Powder) to purge, thereby removing blood accumulation and curing the disease.
What has been described above represents the general rule. I had a grandson named He, aged fourteen or fifteen. He contracted plague which persisted for over twenty days without resolution. His pulse was empty and weak, unresponsive to firm pressure, and he exhibited no symptoms of forgetfulness or madness. He merely slept drowsily throughout the day without waking clearly. Palpation of his abdomen revealed slight pain but no fullness, urgency, or distension. Some physicians proposed tonification, but I strongly opposed it. At that time, I was attending to my son’s illness and had no time to attend to my grandson; he had not taken any medicine. After waiting quietly for several days, he suddenly felt the urge to defecate and passed several dou [a unit of volume] of purple-black blood, instantly becoming clear-headed. Only then did I realize it was blood accumulation. Had tonics been administered at that moment, he would have died immediately. This suffices to show that those who treat plague know only the general rules but not the variations, much like writers and readers who die under the influence of punctuation marks. Can one not be cautious? I record this for the consideration of experts.