寒热循环有定时，疟成权在少阳司，热多阳亢邪归胃（少阳兼阳明，热多寒少或但热不寒
，寒盛阴生病属脾（少阳兼太阴，寒多热少，或但寒不热。）开手二陈平胃属，收功六（君）子补中
（益气汤）规。更闻肾气丸多效（三阴疟三日一发，五更时以姜汤送下肾气丸三钱，三月可效，）姜
术同煎效更奇。
瘟疫症来路两条∶一条自经络而入，辨症治法，与感冒无异，宜服人参败毒散，温覆以
取微汗，俾其从经络入者，仍从经络出也。一条从口鼻而入，一人之病，传染一家以及一乡
一邑。其症发热头痛，口渴胸满，时吐黄涎，宜藿香正气散，大旨在辛香解秽四字，俾其从
口鼻入者，仍从口鼻出也。过此不愈，则传入于里。大热、大渴，自汗者，宜白虎汤以清之
。谵语，大便闭者，宜三一承气汤以下之。若表里之邪俱实，不汗不便者，宜用防风通圣散
，汗下之法，一剂并行而不悖。若过七日，为一经已尽，病仍不愈，及病患素禀不足者，宜
间用六味地黄汤，四物加人参，元参之类以补之，与伤寒治法略同，但此症七日，得大汗战
汗则生，无汗则死。如汗出不至足，俟七日再汗之，生死以汗为主，故列于表证。
（经义）
非瘟病之感异气而病也金匮真言曰夫精者身之本也故藏于精者春不病温素问补遗治法论曰五疫之至皆伤染易无问大小病
状相同此言水大金木土五行之疫俗亦谓为五瘟大抵互相传染医者宜用雄黄研末涂鼻孔内行从客位边入又男子病秽气出于
口女于病秽气出于阴坐立对语之间自宜识得向背。
寒热交替发作且有固定时间，疟疾的形成主要责之于少阳经。若热象明显，阳气亢盛，病邪多归于胃（此为少阳兼阳明证，表现为热多寒少，或仅有发热而无恶寒）；若寒象严重，阴气偏胜，病则属于脾（此为少阳兼太阴证，表现为寒多热少，或仅有恶寒而无发热）。治疗初期宜用二陈汤合平胃散以化痰燥湿，后期收功则宜用六君子汤或补中益气汤以健脾益气。此外，更有传闻肾气丸疗效显著（对于三日一发、每于五更时分发作的三阴疟，可用姜汤送服肾气丸三钱，连续三月可见效），若将干姜与白术同煎服用，效果更为奇特。
瘟疫病症的致病途径主要有两条：第一条是从经络侵入，其辨证施治方法与感冒无异，适宜服用人参败毒散，服药后覆盖衣被以取微汗，使从经络而入的病邪，仍随汗液从经络排出。第二条是从口鼻侵入，一人患病，可传染给全家乃至一乡一邑。其症状表现为发热头痛、口渴胸闷、时常呕吐黄痰，适宜服用藿香正气散，其治疗大旨在于“辛香解秽”四字，使从口鼻而入的病邪，仍从口鼻排出。若经过上述治疗仍未痊愈，病邪则会传入体内深处。若出现大热、大渴、自汗等症状，适宜用白虎汤来清热；若出现胡言乱语、大便闭塞不通，适宜用三一承气汤来攻下。如果表里之邪均呈实证，既无汗出也无大便通畅，适宜使用防风通圣散，发汗与攻下的治法在一剂药中并行不悖。若病程超过七日，标志着一经之气已尽，但病仍未愈，以及患者素体虚弱不足者，适宜间歇性使用六味地黄汤、四物汤加人参、玄参等药物进行补益，这与伤寒的治疗方法大致相同，只是此症在第七日时，若能得大汗或战汗则可生还，若无汗则死亡。如汗出不到足部，需等待七日再次发汗，生死关键在于出汗情况，因此将其列于表证范畴。
（经文义理）
瘟疫并非感受异常之气而导致的疾病。《金匮真言论》说：“精，是身体的根本，所以能固藏精气的人，春季不会患温病。”《素问补遗治法论》说：“五疫流行之时，都会造成相互感染，无论大人小孩，病症表现都相同。”这里指的是水、金、木、土、火五行对应的疫病，世俗也称之为“五瘟”。大体上这些疫病会互相传染，医生宜用雄黄研成粉末涂抹于鼻孔内。行走时从客人座位旁边进入，又男子患病秽气从口出，女子患病秽气从阴部出，坐立交谈之间，自然应当注意辨别朝向。
The alternating chills and fever occur at regular intervals; the formation of malaria (Nüe, 疟疾) is primarily governed by the Shaoyang channel (Shaoyang Jing, 少阳经). If heat predominates due to hyperactive Yang, the pathogenic factor tends to involve the Stomach (this indicates a concurrent Shaoyang and Yangming syndrome, characterized by more heat than cold, or only heat without chills); if cold predominates due to excess Yin, the pathology belongs to the Spleen (this indicates a concurrent Shaoyang and Taiyin syndrome, characterized by more cold than heat, or only cold without fever). Initial treatment should employ Erchen Tang (Two-Aged Decoction) combined with Pingwei San (Stomach-Pacifying Powder) to resolve phlegm and dry dampness, while concluding treatment should utilize Liujunzi Tang (Six-Gentlemen Decoction) or Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) to strengthen the Spleen and augment Qi. Furthermore, it is reported that Shengqi Wan (Kidney-Qi Pill) is highly effective (for Three-Yin malaria occurring every three days, specifically at dawn, taking Shengqi Wan with ginger decoction may yield results over three months); decocting dried ginger (Shengjiang, 生姜) together with Atractylodes macrocephala Rhizome (Baizhu, 白术) yields even more remarkable effects.
The etiology of plague-like diseases (Wenyi, 瘟疫) follows two main pathways: The first enters via the channels and collaterals; its differentiation and treatment are identical to those for common colds (Ganmao, 感冒), making Ren Shen Bai Du San (Ginseng and Imperata Decoction) suitable. Covering the patient to induce slight sweating allows pathogens entering via the channels to exit through them. The second enters via the mouth and nose; one person's illness can infect an entire family, village, or town. Symptoms include fever, headache, thirst, chest fullness, and frequent vomiting of yellow saliva. Huoxiang Zhengqi San (Patchouli and Magnolia Bark Decoction) is appropriate, with the therapeutic principle centered on "pungent-aromatic resolution of foulness," allowing pathogens entering via the mouth and nose to exit through them. If these treatments fail, the pathogen transmits inward. For symptoms of high fever, intense thirst, and spontaneous sweating, Baihu Tang (White Tiger Decoction) is used to clear heat. For delirium and constipation, Sanyi Chengqi Tang (Three-One Cathartic Decoction) is used to purge accumulation. If both exterior and interior pathogens are excess patterns, presenting with neither sweating nor bowel movement, Fangfeng Tongsheng San (Saposhnikovia and Gardenia Decoction) is indicated, where diaphoretic and purgative methods act synergistically in a single dose. If the disease persists beyond seven days—marking the completion of one cycle—or if the patient has a congenital deficiency, intermittent use of Liuwei Dihuang Tang (Six-Ingredient Rehmannia Decoction), Siwu Tang (Four-Substance Decoction) added with Ginseng (Renshen, 人参), and Scrophulariae Radix (Xuanshen, 玄参) is recommended for tonification. This aligns roughly with Shanghan (Cold Damage) treatment principles, except that in this condition, survival depends on achieving profuse sweating or shivering sweat on the seventh day; absence of sweat implies death. If sweating does not reach the feet, wait seven days to induce sweating again. Life and death depend on sweating, hence it is categorized under exterior syndromes.
(Interpretation of Classic Texts)
Plague is not caused by the infection of abnormal qi. *Jinkui Zhenyan* states: "Essence is the root of the body; therefore, those who preserve their essence will not suffer from warm diseases in spring." *Suwen Buyi Zhifa Lun* states: "When the five plagues arrive, they cause mutual infection; regardless of age, the symptoms are identical." This refers to epidemics corresponding to the Five Elements (Water, Metal, Wood, Earth, Fire), commonly known as the "Five Plagues." Generally, these are contagious. Physicians should apply powdered Realgar (Xionghuang, 雄黄) inside the nostrils. When moving, enter from beside the guest's seat. Note that men emit foul qi from the mouth when ill, while women emit it from the genitalia; thus, one must be mindful of orientation during sitting, standing, and conversation.