脉沉为在里而反发其汗则津液越出大便难表虚里实久则谵语也（论见谵语）脉浮紧者法当身疼痛宜以汗解之假令尺
中迟者不可发汗何以知之以荣气不足血少故也（活人云先以小建中汤加黄 如尺脉尚迟再作一剂却服桂枝柴胡二越婢一
汤其汤分小剂和解之愈）
许 一乡人邱生者病伤寒发热头疼烦渴脉虽浮数而无力尺以下迟而弱予曰此虽麻黄证而尺迟弱仲景云尺中迟者荣
气不足血气微少未可发汗予于建中汤加当归黄 令饮翌日脉尚尔其家煎迫日夜督发汗药几不逊矣余忍之但用建中调荣
而已至五日尺部方应遂投麻黄汤啜二服发狂须臾稍定略睡已中汗矣信知此事诚难仲景虽云不避晨夜即宜便治医者亦须
顾其表里虚实待其时日若不循次第临时得安损亏五脏以促寿限亦何足贵哉南史载范云病伤寒恐不得预武帝九锡之庆召
徐文伯诊视以实恳之曰可便得愈乎文伯曰便瘥甚易但恐二年后不复起耳云曰朝闻道夕死犹可况二年乎文伯以火烧地布
桃叶设席置云于其上顷刻汗解扑以温粉翼日果愈云甚喜文伯曰不足喜也后二年果卒夫取汗先期尚促寿限况罔顾表里不
待时日便欲速效乎每见病家不耐病未三四日昼夜促汗医者随情顺意鲜有不败事者予故书此以为戒
少阴病脉细沉数病为在里不可发汗少阴病脉微不可发汗亡阳故也脉濡而弱弱反在关濡反在巅微反在上涩反在下微
则阳气不足涩则无血阳气反微中风汗出而反躁烦涩则无血厥而且寒阳微发汗躁不得眠动气在右不可发汗发汗则衄而渴
心苦烦饮即吐水动气在左不可发汗发汗则头眩汗不止筋惕肉 动气在上不可发汗发汗则气上冲正在心端动气在下不可
发汗发汗则无汗心中大烦骨节苦疼目连恶寒食则反吐谷不得前咽中闭塞不可发汗发汗则吐血气微绝手足厥冷欲得倦卧
不能自温诸脉得数动微弱者不可发汗发汗则大便难腹中干（一云小便难胞中干）胃躁而烦其形相象根本异源脉濡而弱弱
反在关濡反在巅弦反在上微反在下弦为阳运微为阴寒上实下虚意欲得温微弦为虚不可发汗发汗则寒栗不能自还咳者则
剧数吐涎沫咽中必干小便不利心中饥烦 时而发其形似疟有寒无热虚而寒栗咳而发汗蜷而苦满腹中复坚厥脉紧不可发
汗发汗则声乱咽嘶舌萎声不得前诸逆发汗病微者难瘥剧者言乱目眩者死（一云谵言目眩睛乱者死）命将难全太阳病得之
八九日如疟状发热恶寒热多寒少其人不呕清便续自可一日二三度发脉微而恶寒者此阴阳俱虚不可更发汗也太阳病发热
恶寒热多寒少脉微弱者无阳也不可发汗咽喉干燥者不可发汗亡血不可发汗发汗则寒栗而振衄家不可发汗汗出必额上陷
脉急紧直视不能 不得眠汗家不可发汗发汗必恍惚心乱小便已阴疼宜禹余粮丸（方本阙）淋家不可发汗发汗必便血疮家
虽身疼痛不可发汗汗出则痉下利不可发汗汗出必胀满咳而小便利若失小便者不可发汗汗出则四肢厥逆冷伤寒一二日至
四五日厥者必发热前厥者后必热厥深者热亦深厥微者热亦微厥应下之而反发汗者必口伤烂赤伤寒脉弦细头痛发热者属
少阳少阳不可发汗伤寒头痛翕翕发热形象中风常微汗出自呕者下之益烦心懊 如饥发汗则致痉身强难以伸屈熏之则发
黄不得小便久则发咳唾太阳与少阳并病头项强痛或眩冒时如结胸心下痞硬者不可发汗太阳病发汗因致痉少阴病咳而下
利谵语者此被火气劫故也小便必难以强责少阴汗也少阴病但厥无汗而强发之必动其血未知从何道出或从口鼻或从目出
者是名下厥上竭最为难治
永类钤方云伤寒发汗有四难凡发热头疼有汗而非无汗恶风而非恶寒例发其汗汗不止为漏风间有发而为痉者此分外
证发汗之一难也至于发热头痛尺脉迟者为荣虚血少不可发汗发热头痛脉弦细属少阳不可汗汗则谵语此分脉发汗之二难
也动气在左不可汗汗则头眩汗不止则筋惕肉 动气在右不可汗汗则衄而渴心烦饮则吐水动气在上不可汗汗则气冲心动
气在下不可汗汗则无汗心烦骨节疼此分内证发汗之三难也春宜汗不可大发以阳气尚微冬不大汗以阳气伏藏汗之必吐利
口烂生疮此知时发汗之四难也
云 太阳证非头痛项强不可发汗非身热恶寒不可发汗非脉浮不可发汗
活 其脉微弱或尺脉迟者不可表其人当汗而衄血下血者不可表坏病者不可表妇人经水适来者不可表风温者不可表
湿温者不可表虚烦者不可表病患腹间左右上下有筑触动气者不可表太阳咽干鼻衄淋漓小便不利皆不当汗已经发汗不得
重发如无以上忌证虽经发汗邪气未尽亦当重发之当汗不汗则生黄其证为风寒所伤阳气下陷入内而与寒水上行于经络之
间本当发汗以彻其邪医失汗之故生黄也脾主肌肉四肢寒湿与内热相合故生黄也不当汗而汗为蓄血之证燥火也当益津液
为上而反汗以亡之其毒扰阳之极则侵阴也故燥血蓄于胸中也当汗而发汗过多腠理开泄汗漏不止故四肢急难以屈伸也
脉象沉伏，说明病邪在里，如果反而使用发汗法，会导致津液外泄，引起大便干结难解；表气虚弱而里气实，时间久了会出现谵语（神志不清，胡言乱语）的症状。（相关论述见“谵语”章节）
脉象浮紧，按照常理应当出现身体疼痛，适宜用发汗法解除。假如尺部脉搏迟缓，则不可发汗。为什么知道这一点呢？因为营气不足，血液亏少。（《活人书》说：先服用小建中汤加黄芪；如果尺脉仍然迟缓，再服一剂，然后服用桂枝汤、柴胡汤或越婢汤中的一种，这些方剂的剂量要小，以和解的方式治疗，病就好了。）
许学士曾治一位同乡邱生，患伤寒，发热、头痛、烦躁口渴。脉象虽然浮数但无力，尺部以下脉搏迟缓且微弱。我说：这虽然是麻黄汤证，但尺部迟弱，张仲景说过：“尺中迟者，营气不足，血气微少，不可发汗。”我在建中汤中加入当归、黄芪让他服用。第二天脉象依然如此，他的家人煎药催促，日夜督促我发汗药，几乎不给我退路。我忍耐坚持，只用建中汤调和营卫而已。到了第五天，尺部脉象才应指有力，于是投予麻黄汤，连服两剂后，患者发狂，片刻后稍定，略睡一觉后遍身出汗，病就好了。确实相信这件事很难处理。张仲景虽然说“不避晨夜，即宜便治”，但医者也必须顾及其表里虚实，等待适宜的时日。如果不遵循次第，临时只求安适，损伤亏损五脏，缩短寿命，又有什么可贵呢？
《南史》记载范云患伤寒，担心不能赶上武帝九锡之庆的宴会，召徐文伯诊治，诚恳地问他：“可以立刻痊愈吗？”文伯说：“立刻痊愈很容易，但恐怕两年后不再起身（去世）。”范云说：“朝闻道，夕死可矣，何况是两年呢？”文伯烧红地面铺上桃叶，设席让范云躺在上面，顷刻间汗出病解，扑上温粉。次日果然痊愈，范云很高兴。文伯说：“不值得高兴。”两年后果然去世。这种取汗的方法尚且提前促成了寿限的终结，何况是不顾表里虚实，不等待时日，就想求速效的人呢？我常见病人家属不耐受病痛，未过三四日就昼夜催促发汗，医者顺从情欲和意愿，很少有不败事的。所以我写下此文作为警戒。
少阴病，脉细沉数，病位在里，不可发汗。少阴病，脉微弱，不可发汗，因为会亡阳。脉濡而弱，弱脉反见于关部，濡脉反见于巅部（寸部），微脉反见于上部，涩脉反见于下部。微则阳气不足，涩则无血。阳气反微，中风汗出反而躁烦，涩则无血，四肢厥冷而且寒。阳气微，发汗则躁不得眠。动气在右，不可发汗，发汗则鼻衄且渴，心中苦烦，饮水即吐水。动气在左，不可发汗，发汗则头晕目眩，汗不止，筋惕肉瞤。动气在上，不可发汗，发汗则气上冲，正在心端。动气在下，不可发汗，发汗则无汗，心中大烦，骨节苦痛，眼睛畏寒，进食则反吐，谷气不得下行，咽喉闭塞。不可发汗，发汗则吐血，气微绝，手足厥冷，想睡觉但不能自温。各种脉象出现数动而微弱者，不可发汗，发汗则大便难，腹中干（一说小便难，胞中干）。胃燥而烦，其形相像，根本异源。脉濡而弱，弱反在关，濡反在巅，弦反在上，微反在下。弦为阳运，微为阴寒，上实下虚，意欲得温。微弦为虚，不可发汗，发汗则寒栗不能自还。咳者则剧，数吐涎沫，咽中必干，小便不利，心中饥烦，时而发作，其形似疟，有寒无热，虚而寒栗。咳而发汗，蜷卧而苦满，腹中复坚。厥脉紧，不可发汗，发汗则声音混乱，咽喉嘶哑，舌萎软，声音发不出。诸逆证发汗，病轻者难愈，病重者言语错乱、目眩者死（一说谵言、目眩、睛乱者死），性命将难以保全。
太阳病，得之八九日，如疟状，发热恶寒，热多寒少，患者不呕吐，二便清利通畅，一日二三度发作，脉微而恶寒者，这是阴阳俱虚，不可再发汗了。太阳病，发热恶寒，热多寒少，脉微弱者，属无阳，不可发汗。咽喉干燥者，不可发汗。亡血者，不可发汗，发汗则寒栗而振颤。经常鼻衄者，不可发汗，汗出必导致额上凹陷，脉急紧，直视不能闭眼，不得眠。平素多汗者，不可发汗，发汗必恍惚心乱，小便后阴部疼痛，宜用禹余粮丸（原方缺失）。淋家（久患淋病者），不可发汗，发汗必便血。疮家（久患疮疡者），虽身体疼痛，不可发汗，汗出则发生痉病。下利者，不可发汗，汗出必胀满。咳嗽而小便通利，或者失禁者，不可发汗，汗出则四肢厥逆冷。
伤寒一二日至四五日，出现厥冷者，必定会发热；前段厥冷者，后段必定发热。厥深者热亦深，厥微者热亦微。本应攻下而反用发汗法，必定口舌生疮溃烂。伤寒脉弦细，头痛发热者，属于少阳病，少阳病不可发汗。伤寒头痛，翕翕发热，形象像中风，常有微汗出，自己呕吐者，误下则更加烦闷懊恼，如饥感；发汗则导致痉病，身体强直难以伸屈；熏蒸则发黄，不得小便，久了则发咳唾。太阳与少阳并病，头项强痛，或眩晕冒昧，有时像结胸，心下痞硬者，不可发汗。太阳病发汗因致痉。少阴病咳嗽而下利，谵语者，这是被火气劫迫所致，小便必定困难，这是强行责取少阴汗的缘故。少阴病但厥无汗而强行发汗，必定动其血，不知道从哪条道出血，或者从口鼻，或者从眼睛出来，这叫下厥上竭，最为难治。
《永类钤方》说：伤寒发汗有四难。凡是发热头疼，有汗而非无汗，恶风而非恶寒，例当发汗，若汗出不止成为漏风，间或有发而为痉病的，这是分外证发汗的第一难。至于发热头痛，尺脉迟者，为营虚血少，不可发汗；发热头痛，脉弦细属少阳，不可发汗，发汗则谵语，这是分脉发汗的第二难。动气在左不可汗，发汗则头晕目眩，汗不止则筋惕肉瞤；动气在右不可汗，发汗则鼻衄且渴，心烦饮水则吐水；动气在上不可汗，发汗则气冲心动；动气在下不可汗，发汗则无汗，心烦骨节疼，这是分内证发汗的第三难。春季宜发汗，但不可大发，因为阳气尚微；冬季不大汗，因为阳气伏藏，发汗必定吐利、口烂生疮，这是知时发汗的第四难。
云岐子说：太阳证非头痛项强不可发汗，非身热恶寒不可发汗，非脉浮不可发汗。
活人书说：其脉微弱或尺脉迟者，不可发汗。其人当汗而衄血、下血者，不可发汗。坏病者，不可发汗。妇人经水适来者，不可发汗。风温者，不可发汗。湿温者，不可发汗。虚烦者，不可发汗。病患腹间左右上下有筑触动气者，不可发汗。太阳病咽干、鼻衄淋漓、小便不利，皆不当汗。已经发汗不得重发。如无以上忌证，虽经发汗邪气未尽，亦当重发之。当汗不汗则生黄疸，其证为风寒所伤，阳气下陷入内，而与寒水上行于经络之间，本当发汗以彻其邪，医失汗之故生黄也。脾主肌肉四肢，寒湿与内热相合故生黄也。不当汗而汗为蓄血之证，燥火也。当益津液为上，而反汗以亡之，其毒扰阳之极则侵阴也，故燥血蓄于胸中也。当汗而发汗过多，腠理开泄，汗漏不止，故四肢急难以屈伸也。
A deep pulse indicates the pathogen is in the interior; if sweating is induced in error, body fluids will escape excessively, leading to difficult defecation. The exterior becomes deficient while the interior becomes excess; over time, this may result in delirium (incoherent speech due to mental confusion). (See discussion under "Delirium".)
A floating and tight pulse typically presents with body pain and should be treated by inducing sweating. However, if the cun-guan-chi pulse at the chi position is slow, sweating must not be induced. How do we know this? Because Ying Qi (Nutritive Qi) is insufficient and blood is scant. (The *Liu Ren Shu* states: First administer Xiao Jian Zhong Tang (Minor Construct the Middle Decoction) added with Huangqi (Astragali Radix); if the chi pulse remains slow, administer another dose, then take Guizhi Tang (Cinnamon Twig Decoction), Chaihu Tang (Bupleurum Decoction), or Yuebi Tang (Ephedra and Magnolia Bark Decoction) in small doses to harmonize the condition, and the patient will recover.)
Xu Yishi once treated a fellow townsman, Qiu Sheng, who suffered from Shanghan (Cold Damage) with fever, headache, restlessness, and thirst. Although his pulse was floating and rapid, it was forceless, and the pulses below the guan position were slow and weak. I said: "Although this resembles a Mahuang Tang (Ephedra Decoction) pattern, the slow and weak chi pulse indicates, as Zhang Zhongjing stated, 'If the chi pulse is slow, Ying Qi is insufficient, and Qi and Blood are slightly depleted; sweating must not be induced.' I prescribed Jianzhong Tang (Construct the Middle Decoction) added with Danggui (Angelicae Sinensis Radix) and Huangqi (Astragali Radix) for him to drink. The next day, the pulse remained unchanged. His family prepared the decoction urgently, urging me day and night to induce sweating, leaving me little room to refuse. I endured their pressure, using only Jianzhong Tang to harmonize Ying and Wei (Defensive Qi). By the fifth day, the chi pulse finally became responsive. I then administered Mahuang Tang, two doses. After taking them, the patient went mad, but soon calmed down, slept briefly, and then sweated profusely, recovering completely. Indeed, I have come to know that this matter is truly difficult. Although Zhang Zhongjing said, 'Do not avoid morning or night, treat immediately,' physicians must also consider the exterior-interior deficiency-excess patterns and wait for the appropriate timing. If one does not follow the proper sequence and seeks temporary relief without regard for order, damaging the Zang-Fu organs and shortening life span, what value is there?"
The *History of the Southern Dynasties* records that Fan Yun contracted Shanghan and feared he would miss Emperor Wu's celebration of the Nine Bestowals. He summoned Xu Wenbo for diagnosis and asked earnestly, "Can I recover immediately?" Wenbo replied, "Recovering immediately is very easy, but I fear you will not rise again after two years." Yun said, "I heard the Way in the morning and could die content in the evening; how much more so for two years?" Wenbo heated the ground, spread peach leaves, set up a mat, and placed Yun upon it. In an instant, Yun sweated and recovered. Warm powder was applied. The next day, he indeed recovered and was very pleased. Wenbo said, "There is no need to be pleased." Two years later, Yun indeed died. This method of inducing sweating even accelerated his lifespan; how much more so for those who disregard exterior-interior deficiency-excess, do not wait for the proper time, and seek quick results? I often see patients' families unable to tolerate the illness, urging sweating day and night within three or four days. Physicians who comply with these desires rarely avoid failure. Therefore, I write this as a warning.
Shaoyin disease with a fine, deep, and rapid pulse indicates the pathogen is in the interior; sweating must not be induced. Shaoyin disease with a faint pulse cannot be treated with sweating because it leads to Yang collapse. A pulse that is soft and weak, where the weak quality is found at the guan position, the soft quality at the dian (cun) position, the faint quality at the upper part, and the choppy quality at the lower part. Faintness indicates insufficient Yang Qi; choppy indicates lack of Blood. If Yang Qi is faint, wind-stroke causes sweating followed by irritability; choppy indicates lack of Blood, leading to cold limbs and cold sensations. If Yang is faint, inducing sweating causes irritability and inability to sleep. If "moving qi" (abdominal pulsations) is on the right, sweating must not be induced; inducing sweating causes epistaxis and thirst, heart distress, and vomiting water after drinking. If moving qi is on the left, sweating must not be induced; inducing sweating causes dizziness, incessant sweating, tremors of muscles and twitching of flesh. If moving qi is above, sweating must not be induced; inducing sweating causes Qi rushing upward, centered at the heart. If moving qi is below, sweating must not be induced; inducing sweating causes absence of sweat, severe heart distress, painful bone joints, aversion to cold in the eyes, vomiting food after eating, obstruction of grain flow, and throat blockage. Sweating must not be induced; inducing sweating causes hematemesis, faint Qi, cold extremities, desire to lie down, and inability to warm oneself. Any pulse that is rapid-moving yet weak and faint should not be treated with sweating; inducing sweating leads to difficult defecation and dry abdomen (or difficult urination and dry bladder). Stomach dryness and irritability occur; although the manifestations seem similar, their origins differ. A pulse that is soft and weak, weak at guan, soft at cun, wiry at the upper part, and faint at the lower part. Wiry indicates Yang movement; faint indicates Yin cold. Upper excess and lower deficiency indicate a desire for warmth. Faint and wiry indicates deficiency; sweating must not be induced. Inducing sweating causes chills and inability to recover. Coughing worsens, with frequent spitting of saliva, dry throat, difficult urination, and hunger-like heart distress, occurring intermittently like malaria but with cold and no heat, presenting as deficiency with chills. Inducing sweating in coughing leads to curling up, abdominal fullness, and hardness. A tight Jue pulse cannot be treated with sweating; inducing sweating causes voice disorder, hoarseness, tongue flaccidity, and inability to speak. For all adverse conditions, inducing sweating makes mild cases difficult to cure and severe cases fatal (delirium, dizziness, chaotic vision), threatening life.
Taiyang disease lasting eight or nine days, resembling malaria with fever and aversion to cold, more heat than cold, no vomiting, clear and normal bowel movements, occurring two or three times a day, with a faint pulse and aversion to cold, indicates both Yin and Yang are deficient; further sweating must not be induced. Taiyang disease with fever, aversion to cold, more heat than cold, and a faint pulse indicates absence of Yang; sweating must not be induced. Dry throat contraindicates sweating. Loss of blood contraindicates sweating; inducing sweating causes chills and trembling. Patients prone to epistaxis cannot be treated with sweating; sweating causes depression of the forehead, tight pulse, staring gaze, and insomnia. Patients prone to sweating cannot be treated with sweating; inducing sweating causes mental confusion and post-urination genital pain; Yuyuliang Wan (Hematite Pill) is indicated (formula missing). Patients with chronic strangury cannot be treated with sweating; inducing sweating causes blood in stool. Patients with chronic sores, despite body pain, cannot be treated with sweating; inducing sweating causes spasms. Diarrhea contraindicates sweating; inducing sweating causes abdominal distension. Cough with normal urination or incontinence contraindicates sweating; inducing sweating causes cold reversal of the four limbs.
In Shanghan, from one to four days, if Jue (cold limbs) occurs, fever will follow; previous Jue implies subsequent fever. Deeper Jue corresponds to deeper heat; milder Jue corresponds to milder heat. If purgation is indicated but sweating is induced instead, mouth sores and redness will result. Shanghan with wiry-thin pulse, headache, and fever belongs to Shaoyang; Shaoyang contraindicates sweating. Shanghan headache, slight fever resembling wind-stroke, with spontaneous slight sweating and self-induced vomiting, if treated with purgation, increases irritability and inner distress; if treated with sweating, causes spasms, stiff body, and difficulty bending/straightening; if fumigated, causes jaundice, urinary retention, and eventually coughing with sputum. Concurrent Taiyang and Shaoyang disease with stiff neck/headache, dizziness, occasional chest binding sensation, and epigastric hardness contraindicates sweating. Taiyang disease treated with sweating leading to spasms. Shaoyin disease with cough, diarrhea, and delirium results from fire therapy coercion; urination will be difficult due to forced Shaoyin sweating. Shaoyin disease with Jue and no sweat, if forcibly sweated, disturbs Blood, which may exit via mouth, nose, or eyes; this is called Lower Jue and Upper Exhaustion, the most difficult to treat.
*Yong Lei Qian Fang* states there are four difficulties in inducing sweating for Shanghan. First, external signs: Fever and headache with sweating rather than anhidrosis, aversion to wind rather than cold, yet treated with sweating, leading to unceasing sweat (Lou Feng) or spasms. Second, pulse differentiation: Fever and headache with slow chi pulse indicate deficient Ying and scant Blood, contraindicating sweating; fever and headache with wiry-thin pulse belong to Shaoyang, contraindicating sweating (inducing sweating causes delirium). Third, internal signs: Moving qi on the left contraindicates sweating (causes dizziness, muscle twitching); on the right (epistaxis, thirst, irritability, vomiting water); above (Qi rushing to heart); below (no sweat, irritability, bone pain). Fourth, seasonal timing: Spring allows mild sweating as Yang is weak; winter forbids heavy sweating as Yang is hidden (inducing sweating causes vomiting, diarrhea, mouth ulcers, sores).
Yun Qizi states: Taiyang patterns require headache and stiff neck, fever and aversion to cold, and floating pulse before sweating can be induced.
*Liu Ren Shu* states: Faint pulse or slow chi pulse contraindicates sweating. Patients requiring sweating but experiencing epistaxis or bleeding contraindicate sweating. Complicated diseases (Huai Bing) contraindicate sweating. Women with menstruation onset contraindicate sweating. Wind-Warmth contraindicates sweating. Damp-Warmth contraindicates sweating. Deficiency irritability contraindicates sweating. Patients with abdominal pulsations anywhere contraindicate sweating. Taiyang with dry throat, severe epistaxis, or difficult urination contraindicates sweating. Already-sweated patients should not be re-sweated. Without these contraindications, even if previously sweated, if pathogens remain, re-sweating is appropriate. Failure to sweat when indicated leads to Jaundice caused by Wind-Cold injuring Yang, causing Yang to sink internally and Cold-Damp to ascend in meridians; sweating should have cleared the pathogen. Spleen governs muscles and limbs; Cold-Damp combining with internal Heat causes Jaundice. Sweating when inappropriate leads to Blood stasis and Dry Fire. Moistening fluids is superior; sweating destroys them, allowing toxicity to disturb extreme Yang and invade Yin, causing dry Blood to accumulate in the chest. Excessive sweating opens pores, causing unceasing leakage, leading to stiff limbs and difficulty moving.