自汗者，不因发散而自然汗出也。卫气者，卫护皮肤，肥实腠理，禁固津液，使不得妄泄也。痘疹之火，由里达
表，干于卫气，皮肤为之缓，腠理为之疏，津液外泄，故自汗也，凡病自汗，宜遽止之。疮疹初出，自汗实为美证，
乃阴阳气和，荣卫通畅，邪气不留，易出而解也。又，心主汗，诸疮皆属于心，自汗出者，毒瓦斯外泄也，虽然热之甚者，
亦为汗解，身复清凉，此毒散也。若汗出不止，其热反剧，此邪气并于阳而阳虚，宜敛汗固表，清热解毒，使卫气充实，
无痒塌溃烂之患。保元汤（大法）当归六黄汤（盗汗）主之。如疮已收较，痂皮脱落自汗者，此气虚也，宜补阳救
阴，使气无泄，十全大补汤（汗）主之。若更不止，调败蒲散同服，外用温粉扑法。薛
氏云∶靥后最宜审治，若血虚者，用当归补血汤（虚热）。气虚者，用四君子汤加黄 。气血不足者，十全大补汤。
饮食自汗者，小异功散（吐泻）加黄连、五味子、乌梅肉。睡中汗出，心有热也，其汗上至头，下至颈，不过胸者，乃
六
阳虚汗也，不须治之。上至颈，下至脐者，此胃虚也，保元汤（即参 饮见大法）不止，调败蒲散同服。自汗者，
血之所化，阴气不能闭藏，所以睡则汗出，痘家当以补血为主，若当归补血汤、六味地黄丸、八珍汤、人参养荣汤之类，
皆可因证施治。自汗面赤作渴，手足 汗多者，胃热也，泻黄散（脾）人参白虎汤（发热）加黄连主之。诸证退，
以小异功散加山栀仁、麦门冬调之。有食积内热自汗者，四君子加曲 。自汗发搐流涎者，肝木侮土也，小异功散
加钓藤。搐减，去钓藤加柴胡主之。丹溪谓自汗不妨，盖指初出并其汗之不甚者言耳，若汗出过多，最能虚人，
未靥之际，恐致气血虚而不能结痂，既靥之后，尤防血脱阴虚，阳无所附矣。汗出如油，发润如洗，喘不休者，此
为肺绝之候，死不治。
浮麦散
浮麦不拘多少，炒香，每服三五钱，水煎服，治胃虚自汗。
败蒲散（一名止汗散）
用故蒲扇烧灰，每服三钱，温酒调下，无时服。
温粉扑法
黄连 牡蛎粉 贝母（各半两） 粳米粉（一升）
上为细末。敷于身上。
自汗，是指在没有使用发汗药物的情况下，自然出现的出汗现象。卫气的作用是护卫皮肤，使腠理（皮肤纹理及毛孔）致密坚固，固摄津液，防止其无故流失。痘疹的热毒由体内向体表蔓延，干扰了卫气的正常运行，导致皮肤松弛，腠理开泄，津液外泄，从而引起自汗。凡是疾病过程中出现自汗，应当立即予以止汗治疗。但在疮疹初起阶段，自汗实际上是良好的征象，这表明阴阳之气调和，营卫运行通畅，邪气无法滞留，有利于痘疹透发并痊愈。此外，心主司汗液，各类疮疡均归属于心，自汗排出意味着体内的毒热之气向外宣泄。虽然高热严重时，通过出汗也能使病情缓解，身体恢复清凉，这表示毒邪已散。如果汗出不止，且发热反而加重，这是邪气并入阳分而导致阳气虚损的表现，应当采用收敛止汗、固护肌表、清热解毒的方法，使卫气充实，避免发生瘙痒、塌陷、溃烂等并发症。此时可用保元汤（主治大法中的方剂）或当归六黄汤（主治盗汗的方剂）来治疗。如果疮疹已经收口结痂，痂皮脱落时出现自汗，这是由于气虚所致，应当采用补阳救阴的方法，使气不再耗散，可用十全大补汤（主治汗证）来治疗。如果汗出仍然不止，可配合服用调败蒲散，外用温粉扑法。薛己认为：痘疹结痂后最应仔细辨证治疗，如果是血虚引起的，用当归补血汤（主治虚热）；如果是气虚引起的，用四君子汤加黄芪；如果是气血两虚的，用十全大补汤。因饮食不当引起的自汗，用小异功散（主治吐泻）加黄连、五味子、乌梅肉。睡梦中出汗，是心有热所致，如果汗液上至头部，下至颈部，不超过胸部，这是六阳经气虚导致的汗出，不需要特别治疗。如果汗液上至颈部，下至肚脐，这是胃气虚弱所致，用保元汤（即参饮，见大法章节）治疗，如果无效，配合服用调败蒲散。自汗是由血液化生的，阴气不能闭藏，所以睡觉时出汗，患痘疹的人应当以补血为主，如当归补血汤、六味地黄丸、八珍汤、人参养荣汤等，都可以依据具体证候进行治疗。自汗伴有面色发红、口渴、手足心多汗的，是胃热所致，用泻黄散（主治脾热）或人参白虎汤（主治发热）加黄连来治疗。各种症状消退后，用小异功散加山栀仁、麦门冬进行调理。有食积内热导致自汗的，用四君子汤加神曲。自汗伴有抽搐、流涎的，是肝木克制脾土所致，用小异功散加钩藤。抽搐减轻后，去掉钩藤，加柴胡治疗。朱丹溪认为自汗无妨，这指的是痘疹初起以及汗出不多的情况而言。如果汗出过多，最容易使人虚弱，在痘疹未结痂之前，恐怕会导致气血虚弱而不能结痂；在痘疹结痂之后，更要防止血脱阴虚，导致阳气无所依附。如果汗出如油，头发湿润像洗过一样，气喘不停，这是肺气衰竭的征象，属于死证，难以治愈。
浮麦散
浮小麦不拘多少，炒香，每次服用三到五钱，用水煎服，用于治疗胃虚引起的自汗。
Spontaneous sweating refers to the natural occurrence of sweating without the use of diaphoretic (sweat-inducing) medications. Wei Qi (Defensive Qi) functions to protect the skin, ensure the density and solidity of the Cou Li (skin texture and pores), secure body fluids, and prevent their uncontrolled leakage. The heat-toxin of smallpox/rash spreads from the interior to the exterior, interfering with the normal operation of Wei Qi, causing the skin to become lax and the Cou Li to open, leading to the external leakage of body fluids and thus spontaneous sweating. In general diseases, spontaneous sweating should be stopped immediately. However, during the initial eruption of rashes, spontaneous sweating is actually a favorable sign, indicating that Yin and Yang Qi are harmonious, Ying Qi (Nutritive Qi) and Wei Qi are flowing smoothly, pathogenic factors cannot remain stagnant, and it facilitates the eruption and resolution of the rash. Furthermore, the Heart governs sweat, and all sores and ulcers belong to the Heart; spontaneous sweating indicates the external discharge of toxic heat. Although severe heat can also be relieved through sweating, resulting in the body becoming cool again, this signifies the dispersion of toxins. If sweating continues incessantly and fever worsens, it indicates that pathogenic factors have merged into the Yang aspect, leading to Yang deficiency. Treatment should focus on astringing sweat, consolidating the exterior, clearing heat, and detoxifying, to replenish Wei Qi and prevent complications such as itching, collapse, or ulceration. In such cases, Baoyuan Decoction (used for major principles) or Danggui Liu Huang Tang (Cinnamon Twig and Rehmannia Six-Huang Decoction, used for night sweats) may be administered. If the rash has crusted over and scabs fall off, accompanied by spontaneous sweating, this is due to Qi deficiency. Treatment should aim to tonify Yang and rescue Yin, preventing Qi loss, using Shiquan Dabu Decoction (Ten Complete Great Tonifying Decoction, used for sweating disorders). If sweating persists, it can be taken together with Bai Pu San (Decoction of Rotten Cattail Powder), and externally, the Wen Fen Pu Method (Powder Dusting Method) can be applied. Xue Ji stated: After the crusts form, careful differentiation and treatment are essential. If caused by Blood deficiency, Danggui Buxue Tang (Angelica Sinensis and Astragalus Tonifying Blood Decoction, used for deficient heat) should be used; if caused by Qi deficiency, Sijunzi Tang (Four Gentlemen Decoction) plus Huangqi (Astragalus Root) should be used; if caused by both Qi and Blood deficiency, Shiquan Dabu Decoction is appropriate. For spontaneous sweating caused by dietary irregularities, Xiaoyigong San (Minor Extra-merit Powder, used for vomiting and diarrhea) plus Huanglian (Coptis Rhizome), Wuweizi (Schisandra Fruit), and Wumei Rou (Mume Seed Flesh) should be used. Sweating during sleep is caused by Heat in the Heart. If sweat extends from the head to the neck but does not reach the chest, this is spontaneous sweating due to deficiency of the Qi of the Six Yang channels, which requires no specific treatment. If sweat extends from the neck to the umbilicus, this is due to Stomach Qi deficiency, treated with Baoyuan Decoction (equivalent to Shen Yin, see Major Principles); if ineffective, take together with Bai Pu San. Spontaneous sweating is transformed from Blood; when Yin Qi fails to consolidate, sweating occurs during sleep. Patients with smallpox/rash should primarily focus on nourishing Blood. Formulas such as Danggui Buxue Tang, Liuwei Dihuang Wan (Six-Ingredient Rehmannia Pill), Bazhen Tang (Eight-Treasure Decoction), and Renshen Yangrong Tang (Ginseng Nourishing Spirit Decoction) can be prescribed according to the syndrome. Spontaneous sweating accompanied by facial redness, thirst, and excessive sweating on the hands and feet indicates Stomach Heat, treated with Xiehuang San (Drain Yellow Powder, used for Spleen heat) or Renshen Baihu Tang (Ginseng White Tiger Decoction, used for fever) plus Huanglian. After various symptoms subside, regulation can be achieved with Xiaoyigong San plus Zhiren (Gardenia Seed) and Maidong (Ophiopogon Tuber). Spontaneous sweating caused by food stagnation and internal heat is treated with Sijunzi Tang plus Qu (Medicated Leaven). Spontaneous sweating accompanied by convulsions and salivation indicates Liver Wood insulting Spleen Earth, treated with Xiaoyigong San plus Gouteng (Uncaria Ramulus). When convulsions decrease, remove Gouteng and add Chaihu (Bupleurum Root). Zhu Danxi stated that spontaneous sweating is not harmful, referring only to the initial eruption and cases where sweating is mild. However, excessive sweating easily causes debility. Before the crusts form, there is a risk that Qi and Blood deficiency will prevent scabbing; after the crusts form, one must guard against Blood depletion and Yin deficiency, leaving Yang without attachment. If sweat flows like oil, hair is wet as if washed, and panting is ceaseless, this is a sign of Lung Qi exhaustion, representing a fatal condition that is difficult to treat.
Fumai San (Floating Wheat Powder)
Floating wheat, any amount, stir-fried until fragrant. Take 3–5 qian per dose, decocted in water, to treat spontaneous sweating due to Stomach deficiency.
Baipu San (Rotten Cattail Powder, also known as Zhihan San/Stop-Sweat Powder)
Burn old cattail fans to ash. Take 3 qian per dose, mixed with warm wine, to be taken at any time.
Wenfen Pu Method (Warm Powder Dusting Method)
Huanglian (Coptis Rhizome), Moli Fen (Oyster Shell Powder), Beimu (Fritillaria Bulb) (each half liang), Jingmi Fen (Rice Flour) (one sheng).
Grind all ingredients into fine powder. Apply/dust onto the body.