治痘之法，贵乎谨之于始，而虑其所终，庶无后日之悔，经曰∶上工治未病，
中工治将病，下工治已病，未病施治，十全八九，治将病者，十全四五，治已病者，
功莫能施。发热之初，大热渴烦，大便秘，腹痛腰痛，鼻干唇燥，惊悸谵妄，此毒
气郁遏于内，即当防其伏而不出也。吐利不止，即防其中气虚弱，不能助疮成就，
或致倒陷也。故热则解之，便秘则利之，惊则平之，吐利则止之。且如初出一点血，
此春之气，发生之令也。至于起发，此夏之气，长养之令也。水化为浆，此秋之气，
成实之令也。脓干结靥，此冬之气，闭藏之令也。初出而便有水，将发而便戴浆，
脓未成而便收靥，此未至而至，谓之太过，必有陷伏，发表、托里、解毒，切不可
缓。应出不出，应起不起，应收不收，此至而不至，谓之不及，必责以气衰血微，
而匀气、活血、解毒之法，不可不急施也。又如初出色艳者皮嫩，皮嫩则易破，当
防其痒塌也。相聚成块者，不可谓之疏，此有伏也。壳空无水者，后必发痈。头面
预肿者，防其易消而倒陷。咽痛者，急解之，防其失声呛喉也。中多水泡者，后必
自利。目涩泪出者，防其有肤翳也。频更衣者，防其倒靥，疮破不结痂，此倒靥也。
尧夫云∶与其病后才服药，孰若病前能自防。其此之谓欤。
《指南》云∶气色白也，血色红也，痘毒初出之际，血气未定，吉凶未兆，而红
白之形色未分，见于腮耳口鼻年寿之间一点淡红而已，既而其中稍有微白，而外则
淡红如故也，至此而吉凶已判矣。既而根窠丸混而其中之白渐大，而外之淡红渐细，
至此，吉凶悔吝之机着矣。既而其痘形色尖圆光泽，中之白色遂充，而外之红晕渐
细，痘至于此，始有成浆之意，其中白色，略带微黄而又红活也。进而五六日之中，
内之白色虽将变黄，犹未离于红白之间也，外之红圈虽将渐细，而尚未至于微也。
进而六日七日，则中之白色变而纯黄，犹未至于老也，外附红晕，微有一线红润光
洁之色而已。既而八日九日之中，则痘成浆，圆洁饱满，有黄色而无红晕，至此气
血顺序，治定功成矣。至十一十二日，渐见干黄，或如青痘色，气血平复之时也，
虽然，犹有倒靥之患，未可忽也。至十二十三日，干黄皮皱结成老靥，自头面而及
手足者顺也，自手足而及头面者逆也。至十三十四日，则靥老而落矣。然犹有老而
不落之患，名曰漆面刺肉，身体发热，眼红面赤，心烦口渴者有矣，面虚目肿恶心
者有矣，靥老而后，从靥肉溃烂者有矣，身热不退，口生疳蚀，舌生白胎者有矣，
或四肢发毒，或发疔肿者有矣，眼生白障，或眼露白睛者有矣，痘虽平复，祸变百
出，乌得以靥老而不知防乎。靥老脱卸光洁，治痘若愈矣，然犹未也，靥落而疤白
者有矣，有经月之余而犹发寒热者矣，或生流注溃烂，或身生疥癞，或发渴狂烦，
或喘渴不宁，痂虽脱落，余证相仍，死生未可保也。治痘者，又可以痂落为平安哉！
治疗痘疹（天花）的方法，贵在起初谨慎对待，并考虑到最终的结局，这样才不会有日后的后悔。医经说：高明的医生在疾病未发生时就进行干预，一般的医生在疾病即将发生时进行干预，低劣的医生在疾病已经发生后进行治疗。在疾病未发时施治，十次能治好八九次；在疾病将发时施治，十次能治好四五次；在疾病已发时施治，则难以施展功效。
发热之初，出现大热、口渴烦躁、大便秘结、腹痛腰痛、鼻干唇燥、惊悸谵妄等症状，这是毒气郁结阻滞于体内，此时就应当防止痘毒潜伏而不能透发出来。如果呕吐腹泻不止，就要防止中气虚弱，不能助长痘疮成熟，或者导致痘毒内陷。所以，有热邪就用解表法，大便秘结就用通下法，惊悸就用平肝安神法，呕吐腹泻就用止泻法。
况且如痘疹初出时像一点血点，这是春季生发的时令之气。到了起发阶段，这是夏季生长的时令之气。水泡化为脓浆，这是秋季成熟的时令之气。脓液干燥结痂脱落，这是冬季闭藏的时令之气。如果刚初出就有水疱，将要起发时就充满浆液，脓还未形成就收靥结痂，这叫“未到而先到”，称为太过，必然会有痘毒内陷伏匿的情况，发表、托里、解毒之法，切不可迟缓。如果该出的不出，该起的不起，该收的不收，这叫“到了却没到”，称为不及，必定是因为气衰血微，那么匀气、活血、解毒的方法，不可不紧急施行。
又如痘疹初出色泽鲜艳者，皮肉娇嫩，皮肉娇嫩就容易破损，应当防止其因瘙痒而塌陷。聚集在一起成块状的，不能说是稀疏，这是因为有伏毒。外壳空而无水的，后来必然会发生痈肿。头面部预先肿胀的，要防止其容易消退而导致痘毒内陷。咽喉疼痛的，要紧急解除，防止其失声呛喉。中间多水泡的，后来必然自利腹泻。眼睛干涩流泪的，要防止其产生肤翳（角膜云翳）。频繁排便的，要防止倒靥（痘疮未熟先落），疮破而不结痂，这就是倒靥。
尧夫说：“与其病后服药，不如病前自我预防。”说的就是这个道理。
《指南》说：气色白，血色红。痘毒初出之际，血气未定，吉凶征兆未显，红白形色尚未分明，仅在腮部、耳部、口鼻、年寿（鼻准）之间显现一点淡红色而已。随后其中稍有微白，而外部仍保持淡红，至此吉凶已经判定。接着根脚圆润混杂，中间的白色逐渐变大，外部的淡红逐渐变细，至此，吉凶悔吝的机兆显著了。再然后痘疹形色尖圆光泽，中间的白色充盈，外部的红晕逐渐变细，痘疹到了这一步，才开始有化浆的意思，其中的白色略带微黄而又红润鲜活。进而到五六日之中，内部的白色虽然将要变黄，但仍未脱离红白之间；外部的红圈虽然将要变细，但尚未至于微弱。进而到六七日，中间的白色变为纯黄，但还未到老境，外部附着的红晕，仅有一线红润光洁的颜色而已。再然后到八九天之中，痘疹化成脓浆，圆洁饱满，只有黄色而没有红晕，至此气血顺序正常，治疗确定功效已成。到十一二日，渐见干枯发黄，或像青色痘疹的颜色，这是气血平复的时候，虽然如此，仍有倒靥的隐患，不可忽视。到十二三日，干枯黄色皮肤皱缩结成老痂，从头面蔓延至手足的是顺证，从手足蔓延至头面的是逆证。到十三十四日，则痂老脱落。然而还有痂老却不脱落的隐患，名叫漆面刺肉，身体发热，眼红面赤，心烦口渴的情况是有的；面部虚浮目肿恶心的情况是有的；痂老之后，从痂肉处溃烂的情况是有的；身体发热不退，口中生疳蚀，舌上生白苔的情况是有的；或者四肢发毒，或者发疔肿的情况是有的；眼睛生白障，或者眼露白睛的情况是有的。痘疹虽然平复，祸变百出，怎么能因为痂老就不知道防范呢？痂老脱卸光洁，治疗痘疹好像痊愈了，然而还远未结束，痂落后留下白疤的情况是有的；有一个多月以后仍然发寒热的情况是有的；或者生流注（深部脓肿）溃烂，或者身上生疥癞，或者发渴狂烦，或者喘渴不安宁，痂虽脱落，余症相继出现，生死未可保证啊。治疗痘疹的人，又可以把痂落当作平安吗！
The method for treating smallpox (Dou Zhen) emphasizes caution at the beginning and consideration of the final outcome, so as to avoid future regrets. The classics state: The superior physician treats the disease before it arises; the average physician treats it when it is about to arise; the inferior physician treats it after it has arisen. Treating before the disease arises yields success in eight or nine out of ten cases; treating when it is about to arise yields success in four or five out of ten cases; treating after it has arisen leaves little room for efficacy.
At the initial stage of fever, presenting with high fever, thirst, restlessness, constipation, abdominal and lower back pain, dry nose, dry lips, palpitations, and delirium, this indicates toxic qi stagnating and obstructing internally. At this point, one must prevent the toxin from lurking and failing to erupt. If vomiting and diarrhea persist, one must guard against deficiency of Middle Qi (Zhong Qi), which fails to assist in maturing the pustules, potentially leading to involution (Dao Xian). Therefore, heat should be resolved, constipation should be purged, palpitations should be calmed, and vomiting/diarrhea should be stopped.
Consider the initial eruption resembling a single blood spot; this corresponds to the Spring energy of generation. The subsequent rising phase corresponds to the Summer energy of growth. The transformation of vesicles into pus corresponds to the Autumn energy of fruition. The drying and crusting of pus corresponds to the Winter energy of storage. If fluid appears immediately upon initial eruption, or if the pustules fill with fluid before fully rising, or if they crust over before pus forms, this is termed "arriving before due time," known as Excess (Tai Guo). This inevitably leads to involution or hiding of the toxin. Methods such as releasing the exterior, supporting the interior, and detoxifying must not be delayed. Conversely, if eruption, rising, or crusting fails to occur when expected, this is termed "arriving but not arriving," known as Deficiency (Bu Ji). This is invariably attributed to deficient Qi and thin Blood. Methods such as regulating Qi, invigorating Blood, and detoxifying must be applied urgently.
Furthermore, if the initial eruption is bright red, the skin is tender; tender skin breaks easily, so one must guard against collapse due to itching. Clustering into masses does not indicate sparseness but rather hidden toxins. Pustules that are hollow and devoid of fluid will later develop abscesses. Premature swelling of the head and face requires guarding against easy resolution and involution. Sore throat requires urgent relief to prevent loss of voice or choking. Numerous vesicles in the center predict subsequent diarrhea. Dry eyes with tearing require guarding against corneal opacity (Fu Yi). Frequent bowel movements require guarding against premature crusting (Dao Ye); broken sores that fail to scab constitute Dao Ye.
Yao Fu stated: "It is better to prevent oneself before illness than to take medicine after illness." This is precisely what he meant.
The *Zhi Nan* states: Qi color is white, Blood color is red. At the initial emergence of smallpox toxin, Blood and Qi are unsettled, and auspicious/inauspicious signs are indistinct. The differentiation of red and white colors is not yet clear, appearing only as a faint red spot on the cheeks, ears, mouth, nose, and nasal tip (Nian Shou). Subsequently, a slight whiteness appears within, while the exterior remains faintly red; at this stage, fortune and misfortune are determined. Later, the base becomes rounded and mixed, the internal whiteness gradually enlarges, and the external faint redness gradually thins; at this point, the mechanism of fortune, misfortune, regret, and blame becomes apparent. Further on, when the pustules are sharp, round, glossy, and the internal whiteness is full, while the external red halo thins, the pustules begin to show signs of becoming filled with pus. The internal whiteness takes on a slight yellow hue while remaining vibrant and red. Advancing to the fifth or sixth day, although the internal whiteness may turn yellow, it remains between red and white; although the external red circle thins, it is not yet minute. By the sixth or seventh day, the internal whiteness turns pure yellow, though not yet old; the external attached red halo shows only a trace of redness and gloss. By the eighth or ninth day, the pustules mature into pus, round, clean, and plump, yellow without red halos; here, the sequence of Qi and Blood is normal, treatment is established, and efficacy is achieved. By the eleventh or twelfth day, gradual drying and yellowing appear, or the color resembles greenish pustules, indicating a time of Qi and Blood recovery. Although so, the risk of premature crusting remains and cannot be ignored. By the twelfth or thirteenth day, the dried yellow skin wrinkles and forms old crusts. Spreading from head/face to hands/feet is a favorable course (Shun); spreading from hands/feet to head/face is an unfavorable course (Ni). By the thirteenth or fourteenth day, the old crusts fall off. However, there is the hazard of old crusts failing to fall off, named "Lacquer Face Piercing Flesh," accompanied by body fever, red eyes and face, irritability, and thirst. There are cases of facial puffiness, swollen eyes, and nausea. There are cases where ulceration occurs from the crust flesh after crusting. There are cases of persistent fever, oral ulcers (Gan Shi), and white tongue coating. There are cases of toxicity in the four limbs or development of carbuncles (Ding Zhong). There are cases of white obstructions in the eyes or exposure of the sclera. Even if the smallpox has resolved, myriad disasters may arise; how can one neglect prevention simply because the crusts have aged? If the crusts fall off cleanly and smoothly, the treatment seems successful, yet it is not finished. There are cases of white scars remaining after crusts fall. There are cases of lingering chills and fever for over a month. There are cases of deep-seated abscesses (Liu Zhu) ulcerating, skin diseases like scabies and leprosy-like eruptions, thirst with mania and restlessness, or panting with thirst and agitation. Although the scabs have fallen, residual symptoms persist, and life or death cannot be guaranteed. Can those treating smallpox consider the falling of scabs as safety?