西席汪幼纯先生，盱人也，家洪泽湖之蒋坝镇。一日为予言，吾乡有所谓汗病者，每发
于三四月间，一人患此，即举家传染，同时并发。其证初起觉毛耸，即发热昏卧，不省人事
，不言不动不食，但口渴索饮，日夜不休，若家有五六病患，以一人供茶水不给也。至六七
日，必大发狂躁，汗出乃愈，未有药治者，若不能狂躁，即不起矣。此何病也?予沉思良久
，曰∶此即伤寒也。必冬日天之寒风，与湖之水气相合，人自口鼻吸受，伏于膜原，不与荣
卫出入之道相触，故不实时发；交夏心中阳气当升，而寒湿所伏适当其冲，阻其升发之气
，
遂相激而成病矣。西医谓人脑气受伤，则知觉、运动之灵皆失。脑气与心气相根据者也。心气
为伏寒所扑，与手少阴直中之伤寒相似，此仲景所未言者。其年冬月有异风，挟水邪而至，
人受之者，斯为病矣。故每三五年而一见，盖与运气相关也。未病之先，邪气内伏，必当有
头脑时或沉重，隐隐痛胀，心气偶然一阵如闷之状。治法，桂枝、麻黄皆不合格，当以小青
龙加生津药主之，以中有桂枝、细辛，能入心宣阳而散寒水也。若欲预防，则先于立春之月
，多服桂枝汤可矣。发病之时，脉必沉伏不见，或沉紧细数；未病之先，其脉必紧小不盛也
。此不过一时据理拟议之词，实未知汗病果何义也。嗣读《千金方》，乃知汗病即伤寒之别
名也。俗每谓不可用药，须俟自愈，枉死者多，是敝俗已千余年矣。仲景《辨脉》有曰∶病
至六七日，手足三部脉皆至，大烦，口噤不能言，其人躁扰者，为欲解也。情形与此符合，
但未明六七日间，当用何药，岂束手坐待耶?此病若邪重，当时即发，卒倒无知者，即为手
少阴中寒也。(拙注仲景《辨脉》此条，谓其人躁扰句是眼目，若无此，则烦，噤乃气脱也
。观此益醒。)
西席汪幼纯先生，是盱眙人，家住洪泽湖边的蒋坝镇。有一天他对我说，我们家乡有一种叫“汗病”的病，通常在三四月间发作。如果一个人得了这个病，全家都会被传染，同时发病。这种病刚起时，感觉毛孔竖起，随即发热、昏睡，不省人事，不说话、不动弹、不吃东西，只是口渴想喝水，日夜不停，如果家里有五六个病人，光靠一个人供应茶水都忙不过来。到了第六七天，必定会大发狂躁，出汗后才会痊愈，没有用药物治疗的；如果不能出现狂躁症状，就会死亡。这是什么病呢？我沉思了很久，说：这就是伤寒（外感风寒所致的疾病）。一定是冬天天上的寒风，与湖面的水气相结合，人从口鼻吸入，潜伏在膜原（半表半里的部位），不与营卫（运行于脉内和脉外的气血）出入的道路相接触，所以不会立即发作；到了夏天，心中阳气应当升发，而潜伏的寒湿之气正好冲击这一过程，阻碍了阳气的升发，于是相互激荡而生病。西医认为人的脑气受伤，那么知觉、运动的灵性都会丧失。脑气是与心气相互依存的。心气被伏藏的寒气所打击，这与手少阴心经直中的伤寒相似，这是张仲景没有明确论述过的。那年冬天有异样的风，夹带水邪而来，人受到这种邪气，就得了这个病。所以每三五年才出现一次，大概与运气（五运六气）有关。在未发病之前，邪气内伏，一定会有头脑有时沉重、隐隐作痛胀满，心气偶尔一阵像闷堵的感觉。治疗方法，桂枝汤、麻黄汤都不合适，应当用小青龙汤加生津药为主方，因为方中有桂枝、细辛，能入心宣通阳气而散寒水。如果想要预防，那么在立春之月，多服用桂枝汤就可以了。发病之时，脉象必定沉伏不见，或者沉紧细数；未发病之前，脉象必定紧小而不盛大。这不过是我一时根据医理推测的话，实际上并不知道“汗病”究竟是什么意思。后来读到《千金方》，才知道汗病就是伤寒的别名。民间常说不能用药物，必须等待自愈，枉死的人很多，这种陋习已经存在一千多年了。张仲景《辨脉》篇中说：病到第六七天，手足三部脉都至，大烦闷，口噤不能说话，其人躁扰不安的，是病情将要解除的表现。情形与此相符，但没有说明在第六七天之间，应当用什么药，难道要束手坐等吗？这个病如果邪气重，当时就发作，突然倒下无知觉的，就是手少阴中寒。（我在拙注张仲景《辨脉》这一条时，认为“其人躁扰”句是关键，如果没有这一点，那么烦闷、口噤就是气脱了。看了这段文字更加清醒。）
Mr. Wang Youchun, a private tutor (Xixi), was from Xuyi and resided in Jiangba Town on the banks of Hongze Lake. One day he told me, "In our hometown, there is a disease called 'Sweat Disease' (Han Bing). It usually occurs between March and April. If one person contracts it, the entire household becomes infected, with simultaneous onset. Initially, the patient feels their hair standing on end, followed by fever, stupor, loss of consciousness, inability to speak, move, or eat. They only thirst for drinks, day and night without cease; if there are five or six patients at home, one person cannot possibly supply enough tea and water. By the sixth or seventh day, they must become severely manic and restless; recovery follows sweating. There is no medical treatment for it; if mania does not occur, death ensues. What disease is this?" I pondered for a long time and said, "This is Taiyang Shanghan (Cold Damage affecting the Taiyang channel)." It must be that the cold wind of winter combined with the moisture from the lake was inhaled through the mouth and nose, lying dormant in the Membrane Source (Moyuan, a location between the exterior and interior). Because it did not interact with the pathways of Ying and Wei (Nutritive and Defensive Qi) entering and exiting, it did not manifest immediately. When summer arrived, the Yang Qi of the Heart should ascend, but the latent Cold-Dampness struck directly against this process, obstructing the ascending Qi. Thus, they agitated each other, causing illness. Western medicine posits that injury to the brain's Qi results in the loss of perception and motor functions. Brain Qi relies on Heart Qi. The Heart Qi is suppressed by latent Cold, resembling Cold Damage directly attacking the Hand-Shaoyin (Heart) channel, a scenario not explicitly discussed by Zhang Zhongjing. In that winter, an abnormal wind carrying Water Pathogen arrived; those who contracted it developed this disease. Hence, it appears once every three to five years, likely related to Yunqi (Five Movements and Six Qi theory). Before illness onset, while pathogens lie dormant internally, there must be occasional heaviness in the head, dull pain and distension, and occasional sensations of chest oppression due to Heart Qi disturbance. Regarding treatment, Guizhi Tang (Cinnamon Twig Decoction) and Mahuang Tang (Ephedra Decoction) are inappropriate. Instead, Xiao Qing Long Tang (Minor Blue Dragon Decoction) combined with fluids-generating herbs should be used as the principal formula, because it contains Guizhi (Ramulus Cinnamomi) and Xixin (Asari Radix et Rhizoma), which enter the Heart to disseminate Yang Qi and disperse Cold-Water. For prevention, taking Guizhi Tang frequently during the month of Lichun (Start of Spring) would suffice. During the acute phase, the pulse must be deep, hidden, or invisible, or deep, tight, fine, and rapid. Prior to onset, the pulse must be tight and small, not vigorous. This is merely my speculative reasoning based on principles; I actually do not know the true meaning of 'Sweat Disease.' Later, upon reading Qianjin Fang (Prescriptions Worth a Thousand Gold), I learned that Sweat Disease is another name for Shanghan. Folk custom often claims medication is contraindicated and one must wait for spontaneous recovery, leading to many unnecessary deaths; this bad habit has existed for over a thousand years. Zhang Zhongjing's Bian Mai Lun (Treatise on Pulse Differentiation) states: 'When the disease reaches the sixth or seventh day, if the pulses at the hand and foot三部 (three positions) all arrive, accompanied by severe vexation, lockjaw preventing speech, and restlessness, this indicates the disease is about to resolve.' The clinical presentation matches this description, yet it does not specify what medication to use between the sixth and seventh days. Should one simply sit idle? If the pathogen is heavy and the disease manifests immediately with sudden collapse and unconsciousness, it constitutes Cold attacking the Hand-Shaoyin channel. (In my commentary on this passage in Bian Mai Lun, I stated that 'restlessness' is the key indicator; without it, vexation and lockjaw would indicate Qi collapse. Reading this clarifies the matter further.)"