痘疹自汗者，以阴中之火自里及表，达于卫气，故皮肤为之缓，腠理为之疏，津液流行，
故多自汗，但得痘疹身常潮润，实为美证。此乃阴阳气和，血脉通畅，盖热随汗减，毒随汗散，
邪不能留，则易出易解，虽见热甚，而汗出之后身必清凉，此即毒之消散也，不必治之。
然只宜微汗不宜大汗，若汗出过多，则阳气泄而卫气弱，恐致难救难靥，或为痒 寒战之患，
此则速宜固表以敛其汗也。又有汗出不止，其热反甚者，此邪热在表，阴为阳扰之患，速宜清
火解毒，阳邪退而汗自敛也。若汗出如油，或发润如洗而喘不休者，此肺脱之证，不可治。
一、别无邪热，但以卫气虚，肌表不固而多汗者，调元汤倍加黄 ，或白术散。
一、脾虚于中，卫虚于外，肌肉无主，别无他证而汗不敛者，人参建中汤。
一、心气虚，神怯多惊而汗不固者，团参散。
一、或吐或泻，气脱于中，阳脱于外，而汗出不收，微者五福饮加炮姜、枣仁。甚至手足
厥冷，或呕恶不止而汗不收者，速宜人参理阴煎，或六味回阳饮，迟则恐致不救。
一、阴中火盛，或身有大热而汗多不收者，当归六黄汤。
一、睡中汗出不收者，以阳入阴中，而阴不能静也，当归六黄汤。
一、阳明热盛，火邪燔灼肌肉，或身热烦渴，或二便热涩而汗不收者，人参白虎汤，或
加黄连。
一、收靥痂脱之后，自汗不止者，此邪去而气虚也，宜十全大补汤，或调止汗散，或以滑
石粉扑之。
Spontaneous sweating in smallpox and measles is caused by fire from the yin aspect spreading from the interior to the exterior, affecting the Wei Qi (Defensive Qi), causing the skin to relax and the Cou Li (pores) to open. Consequently, body fluids flow outward, resulting in spontaneous sweating. As long as the body remains slightly moist during the eruption of lesions, this is actually a favorable sign. It indicates the harmony of Yin and Yang and the smooth flow of blood vessels. Heat is reduced with sweat, and toxins are dispersed with sweat; pathogenic factors cannot remain, making it easy for lesions to emerge and resolve. Even if severe heat is observed, the body will become cool after sweating, which signifies the dissipation of toxins; no specific treatment is required.
However, only slight sweating is appropriate, not profuse sweating. If sweating is excessive, Yang Qi will be depleted and Wei Qi weakened, potentially leading to difficulties in lesion crusting or complications such as itching and chills. In such cases, one should quickly secure the exterior to arrest sweating. If sweating persists and fever worsens, this indicates pathogenic heat at the exterior disturbing Yin due to Yang; one should quickly clear fire and detoxify, so that when Yang pathogenic factors recede, sweating naturally stops. If sweat is like oil, or hair is wet as if washed, accompanied by unceasing panting, this is a syndrome of Lung Qi collapse, which is incurable.
1. If there is no other pathogenic heat, but spontaneous sweating occurs solely due to Wei Qi deficiency and insecure muscle exterior, use Tiao Yuan Tang (Regulate Yuan Decoction) with doubled Huang Qi (Astragali Radix), or Bai Zhu San (Atractylodes Powder).
2. If Spleen deficiency is internal and Wei Qi deficiency is external, leaving muscles without control, and sweating does not stop despite other symptoms being absent, use Ren Jian Zhong Tang (Ginseng Build the Middle Decoction).
3. If Heart Qi is deficient, spirit is timid and prone to fright, and sweating is not secured, use Tuan Shen San (Round Ginseng Powder).
4. If vomiting or diarrhea leads to Qi collapse in the middle and Yang collapse on the outside, resulting in unrestrained sweating: for mild cases, use Wu Fu Yin (Five Blessings Drink) with Pao Jiang (Prepared Ginger) and Zao Ren (Ziziphi Spinosomi Semen); for severe cases involving cold extremities or incessant nausea/vomiting with unrestrained sweating, quickly use Ren Li Yin Jian (Ginseng Regulating Yin Decoction) or Liu Wei Hui Yang Yin (Six-Ingredient Restore Yang Drink); delay may lead to untreatability.
5. If fire in the Yin aspect is vigorous, or high fever accompanies unrestrained sweating, use Dang Gui Liu Huang Tang (Angelica Hexapartite Yellow Decoction).
6. If night sweats persist, it is because Yang enters Yin, but Yin cannot remain tranquil; use Dang Gui Liu Huang Tang (Angelica Hexapartite Yellow Decoction).
7. If Yangming heat is excessive, with fire blazing through muscles, accompanied by fever, irritability, thirst, or hot/obstructed urination and defecation with unrestrained sweating, use Ren Bai Hu Tang (Ginseng White Tiger Decoction), or add Huang Lian (Coptidis Rhizoma).
8. After lesions have crusted and scabs fallen off, if spontaneous sweating persists, this indicates pathogens have left but Qi is deficient; use Shi Quan Da Bu Tang (Ten Substance Great Tonifying Decoction), or Diao Zhi Han San (Regulate Stop Sweat Powder), or apply Hua Shi Fen (Talcum Powder) externally.