今之医者，见人有外感，即曰上时邪，即断之曰此七天症，七日不解，则曰十四天症。
不知外因之症有三∶曰伤寒，曰时邪，其轻者则曰感冒。
惟伤寒必讲传经，《内经》有之∶一日太阳，二日阳明，三日少阳，四日太阴，五日少
阴，
六日厥阴；至七传经尽，而太阳病衰，八日而阳明病衰，九日而少阳病衰，十日而太阴病衰
，十一日而少阴病衰，十二日而厥阴病衰。治之各通其脏脉，病日衰已矣。此不过本七日来
复之义，并无复传之说。复传之说，出成无己注释之谬，前人马元台早批驳之。盖厥阴至太
阳有数经之隔，岂有遽出而传太阳之理?即七日传经，在《内经》亦明白示人，知在太阳，
即在太阳治之，不必待传阳明也；知在阳明，即在阳明治之，不必待传少阳也；知在阳分，
即在阳分治之，不必待传入阴分也。且所谓一日
、二日者日字，亦不可呆讲，犹言一传、二传耳!盖人有虚实不同，有胃气素旺，太阳受邪
，经二、三日而不传阳明者；有卫气本虚，始终太阳之邪不去者。岂可以呆法治之?凡此之
论，乃论伤寒也，而江南无正伤寒，如仲景麻黄等汤，殊不合用。
大抵时邪居多。所谓时邪者，冬寒、春温、夏暑、秋凉，受之者曰时邪；又有冬宜寒而
温，
春宜温而寒，夏宜热而凉，秋宜凉而热，所谓非时之寒热，故直谓之时邪。其受寒凉，有由
太阳而入者，必有头项痛、腰脊强等症；或传阳明，必有身热、目痛、鼻干、不得卧等症；
或传少阳，必有胁痛，耳沉、口苦等症。此当按三阳治法，勿使传里，此所谓小伤寒也，但
亦当小其治耳!其受温热者，大抵由口鼻而入，不走太阳，每由阳明而达膜原，失治则易侵
心胞，有神烦、谵语之虑。治宜辛凉，凉药为主，辛药为佐。若夏令炎热太过，致烦热、无
汗，此必用白虎汤，或天生白虎汤服之，即大汗而解。但必先审其大渴欲冷冻饮料，乃真受热，
否则亦不可妄投也。
若夫感冒，不过些微外感，小小疏散，或有停滞，稍加消导宣通，不难一药而愈。乃医
者，
亦曰此七天症候。初感未免兼有寒热，乃曰此作疟未正，多用柴胡，欲其成疟。不知柴胡为
少阳经药，感冒初起，无在少阳经者。柴胡诛伐无过，感冒不转难去耶?更有见感冒即曰时
邪者，治以《温疫论》之达原饮，不愈，即转用下法，以致害人而无悔，尤可叹也!
夫《温疫论》作于吴又可，伊芳乃明末人，其时兵荒相继，百姓流离，死于沟壑者不知几
千万
，其尸气化为厉气，流行于天壤之间，中其气者，延门逐户，无不受病，且传染无穷，古方
虽间有温疫，而无以温疫成书者。吴又可窥破病由口鼻而入，邪在膜原，遂立达原饮，且宜
急下，故方多用下法。其时治必有效，因特撰《温疫论》二卷，独开生面，未尝非医家之一
助。然其书义理粗率，不求精详，果遇温疫之年，可用其法。今之时邪，并非温疫，何可妄
用?若夫视时邪无异温疫，初诊即用达原饮，草果、浓朴屡进，以致燥热不堪，旋即以大黄
下
之，幸而生者，且以为功，不幸而死，则以为病本不治，其实有以致之也。以达原饮治时邪
，不知出于何典，可怪哉!尤可诧者，或有重劳倦，未免寒热，而亦治同时邪，投以达原饮
。夫劳倦发热不重，有汗不退，乃阴虚也，而误为时邪遏伏，妄用达原，致犯虚虚之戒，遗
人祸殃。予亲友中被害不悟者有之，徒令予为之浩叹而已。吾家有习医者，务须博览群书，
精求义理，勿贪一书之简易，孟浪施治也。大抵劳倦之寒热，似乎外感者甚多，然必有辨其
热
必不甚，且按之愈重，则热愈轻，寒亦若有若无，或轻或重，得暖便解，热时或有微汗，仍
不退热，其手心之热必甚于手背，或兼头疼，或时疼时止，或重或轻，虽身体倦痛，精神疲
困，而人事清白，无神糊谵语之象。此则调其气血，安心静养，自然痊可。更有劳倦伤阴，
汗不退热，则以生地、当归辈养阴清热，热自退而病自愈。若误以外感治之，必犯虚虚之戒
，再以时邪遏伏治之，妄用达原饮，鲜有不杀人者。
现在的医生，看到有人患有外感病，就说是染上了时邪，随即断定这是“七天症”；如果七天没有痊愈，就说是“十四天症”。
他们不知道外感病因主要有三种：一是伤寒，二是时邪，其中较轻的称为感冒。
只有伤寒才讲究传经规律，《黄帝内经》中有记载：第一天病在太阳经，第二天在阳明经，第三天在少阳经，第四天在太阴经，第五天在少阴经，第六天在厥阴经；到了第七天传经结束，太阳经的病势衰退，第八天阳明经病势衰退，第九天少阳经病势衰退，第十天太阴经病势衰退，第十一天少阴经病势衰退，第十二天厥阴经病势衰退。治疗时应分别疏通各脏腑的经脉，疾病就会日渐消退痊愈。这不过是依据“七日周期循环”的道理，并没有所谓“再次传变”的说法。“复传”的说法，出自成无己注释的错误，前人马元台早已驳斥过。因为从厥阴经到太阳经中间隔着好几条经脉，怎么会有突然传出太阳经的道理呢？即使按照《内经》所说的七日传经，也明确告诉人们：知道病在太阳经，就在太阳经治疗，不必等到它传到阳明经；知道病在阳明经，就在阳明经治疗，不必等到它传到少阳经；知道病在阳分，就在阳分治疗，不必等到它传入阴分。况且所谓“一日、二日”中的“日”字，也不应死板地理解为天数，它只是表示第一次传变、第二次传变的意思罢了！因为人的体质有虚实的不同，有的人胃气本来旺盛，太阳经受邪后，经过两三天也不会传到阳明经；有的人卫气本来虚弱，始终停留在太阳经的病邪也无法去除。怎么能用死板的方法治疗呢？以上这些论述，都是针对伤寒而言的，而江南地区没有真正的伤寒，像张仲景所用的麻黄汤等方剂，特别不合适用。
大抵来说，时邪居多。所谓的时邪，是指冬季受寒、春季受温、夏季受暑、秋季受凉，感染这些气候因素的人称为时邪；又有冬季本该寒冷却温暖，春季本该温暖却寒冷，夏季本该炎热却凉爽，秋季本该凉爽却炎热，这种非正常季节的寒热变化，所以直接称为时邪。时邪中受寒凉的，有由太阳经侵入的，必然会出现头项痛、腰脊强直等症状；或者传到阳明经，必然出现身体发热、眼睛疼痛、鼻子干燥、无法安卧等症状；或者传到少阳经，必然出现胁肋疼痛、耳朵沉重、口苦等症状。这时应当按照三阳经的治疗方法处理，不要使病邪传入里部，这就是所谓的“小伤寒”，但也应当采用轻小的治法。时邪中受温热的，大抵由口鼻侵入，不走太阳经，往往由阳明经到达膜原（半表半里的部位），如果失治则容易侵犯心包络，会有神志烦躁、说胡话的担忧。治疗宜用辛凉之法，以凉药为主，辛药为辅。如果在夏季炎热过度，导致烦热、无汗，这时必须使用白虎汤，或天生白虎汤服用，即可大汗出而病解。但必须先审察患者是否有大渴欲饮冷冻饮料的表现，这才是真正的受热，否则也不可妄加投药。
至于感冒，不过是轻微的外感，稍微进行疏散治疗，如果有食积停滞，稍加消导宣通的药物，不难一药而愈。然而有些医生，也说这是“七天症候”。初感难免兼有寒热症状，就说这是发作疟疾但未定型，多用柴胡，想让它发展成疟疾。不知道柴胡是少阳经的药，感冒初起，没有病在少阳经的。柴胡会诛伐无辜的正气，感冒不反而难去吗？更有甚者，见到感冒就说是时邪，用《温疫论》中的达原饮治疗，如果不愈，就转而使用下法，以致害人性命而不知悔改，尤其令人叹息！
《温疫论》是吴又可所著，他是明末人，当时战乱饥荒相继发生，百姓流离失所，死于沟壑者不知几千万，尸体之气化为厉气，流行于天地之间，感染这种气的人，满门逐户，没有不受病的，而且传染无穷，古代医方虽然间或有温疫记载，但没有专门以温疫成书的。吴又可洞察到病邪由口鼻而入，邪气在膜原，于是创立达原饮，且适宜急下，所以方中多用下法。在当时治疗必定有效，因此特意撰写《温疫论》二卷，独辟蹊径，未尝不是医家的一助。然而他的书义理粗糙率略，不求精细详备，果然遇到温疫之年，可以用他的方法。现在的时邪，并非温疫，怎么可以妄加使用？如果把时邪看作与温疫无异，初诊就用达原饮，草果、厚朴屡进，导致燥热不堪，随后又用大黄攻下，幸好活下来的，还认为是功劳，不幸死亡的，就说是病本不治，其实是有原因的。用达原饮治时邪，不知出于什么典籍，真是奇怪！尤其令人诧异的是，有的因重劳倦，难免寒热，也当作同时邪治疗，投以达原饮。劳倦发热不重，有汗不退，这是阴虚，却误认为时邪遏伏，妄用达原饮，致使犯了“虚虚”（使虚者更虚）的禁忌，给人带来祸殃。我亲友中被害而不醒悟的有之，徒令我为之长叹而已。我家有学医的人，务必博览群书，精求义理，不要贪图某本书的简易，轻率施治。大抵劳倦引起的寒热，似乎外感的很多，然而必须有辨别：其热必不甚，且按压后热度反而减轻，则热感更轻，寒也若有若无，或轻或重，得暖便缓解，发热时或有微汗，仍不退热，其手心的热必甚于手背，或兼头疼，或时疼时止，或重或轻，虽然身体倦痛，精神疲困，但人事清醒，无神志模糊、说胡话的现象。这时调理气血，安心静养，自然痊愈。更有劳倦伤阴，汗出不退热，则以生地、当归之类养阴清热，热自退而病自愈。如果误以外感治疗，必犯“虚虚”的禁忌，再以时邪遏伏治疗，妄用达原饮，鲜有不杀人的。
Current physicians, upon seeing patients with exogenous diseases, immediately claim they have contracted "Shi Xie" (Seasonal Pathogenic Factors), and subsequently diagnose it as a "Seven-Day Syndrome"; if it does not resolve within seven days, they label it a "Fourteen-Day Syndrome."
They are unaware that there are three main categories of exogenous etiology: one is Shang Han (Cold Damage), the second is Shi Xie (Seasonal Pathogenic Factors), and the milder form is referred to as Gan Mao (Common Cold).
Only in Shang Han (Cold Damage) is the progression through meridians discussed. The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: On the first day, the disease is in the Taiyang (Greater Yang) meridian; on the second day, in the Yangming (Bright Yang) meridian; on the third day, in the Shaoyang (Lesser Yang) meridian; on the fourth day, in the Taiyin (Greater Yin) meridian; on the fifth day, in the Shaoyin (Lesser Yin) meridian; and on the sixth day, in the Jueyin (Terminal Yin) meridian. By the seventh day, the transmission cycle completes, and the pathogenic factor in the Taiyang meridian begins to wane; by the eighth day, the Yangming pathogen wanes; by the ninth day, the Shaoyang pathogen wanes; by the tenth day, the Taiyin pathogen wanes; by the eleventh day, the Shaoyin pathogen wanes; and by the twelfth day, the Jueyin pathogen wanes. Treatment should focus on unblocking the respective organ meridians, after which the disease will gradually decline and resolve. This merely follows the principle of the seven-day cycle and does not support the theory of "re-transmission." The concept of re-transmission stems from erroneous annotations by Cheng Wuji, which were long ago refuted by Ma Yuantai. Since there are several meridians separating the Jueyin from the Taiyang, how could the pathogen suddenly transmit directly to the Taiyang? Even according to the seven-day transmission described in the *Neijing*, it clearly instructs practitioners: if the disease is known to be in the Taiyang, treat it in the Taiyang without waiting for it to transmit to the Yangming; if in the Yangming, treat it in the Yangming without waiting for transmission to the Shaoyang; if in the Yang aspect, treat it in the Yang aspect without waiting for it to enter the Yin aspect. Furthermore, the term "day" in "first day, second day" should not be interpreted rigidly as calendar days, but rather indicates the sequence of transmissions (e.g., first transmission, second transmission). Human constitutions vary in deficiency and excess. Some individuals have robust Stomach Qi; when the Taiyang meridian is affected, the pathogen may remain there for two or three days without transmitting to the Yangming. Others have inherently weak Wei Qi (Defensive Qi), causing the Taiyang pathogen to persist throughout. How can rigid methods be applied universally? These discussions pertain specifically to Shang Han (Cold Damage). In the Jiangnan region, true Shang Han (Cold Damage) is rare, making formulas such as Mahuang Tang (Ephedra Decoction) used by Zhang Zhongjing largely inappropriate.
Generally, Shi Xie (Seasonal Pathogenic Factors) are most common. Shi Xie (Seasonal Pathogenic Factors) refers to pathogens contracted from winter cold, spring warmth, summer heat, or autumn dryness/cold. Additionally, abnormal seasonal temperatures—such as winter being warm instead of cold, spring being cold instead of warm, summer being cool instead of hot, or autumn being hot instead of cool—are also classified as Shi Xie (Seasonal Pathogenic Factors). When Shi Xie (Seasonal Pathogenic Factors) involves cold and chill, entering via the Taiyang (Greater Yang) meridian, symptoms necessarily include headache and stiffness of the head and neck, and rigidity of the lower back and spine. If it transmits to the Yangming (Bright Yang) meridian, symptoms necessarily include fever, eye pain, nasal dryness, and insomnia. If it transmits to the Shaoyang (Lesser Yang) meridian, symptoms necessarily include hypochondriac pain, heavy sensation in the ears, and bitter taste in the mouth. In these cases, treatment should follow the methods for the Three Yang meridians to prevent the pathogen from penetrating inward. This is referred to as "Minor Shang Han (Cold Damage)," requiring mild therapeutic approaches. When Shi Xie (Seasonal Pathogenic Factors) involves warmth and heat, it generally enters via the mouth and nose, bypassing the Taiyang (Greater Yang) meridian, often reaching the Membrane Source (Mo Yuan, a location between the exterior and interior) via the Yangming (Bright Yang) meridian. If left untreated, it easily invades the Pericardium (Xin Bao), leading to concerns about mental restlessness and delirious speech. Treatment should employ acrid-cool methods, primarily using cooling herbs with acrid herbs as auxiliaries. If excessive summer heat causes irritability and anhidrosis (absence of sweating), Baizhu Tang (White Tiger Decoction) or Tiansheng Baizhu Tang must be used to induce profuse sweating and resolve the condition. However, one must first verify the presence of intense thirst craving for cold beverages to confirm true heat retention; otherwise, these drugs should not be administered recklessly.
Gan Mao (Common Cold) involves only slight exogenous invasion, requiring mild dispersing treatments. If accompanied by food stagnation, adding digestive and promoting circulation agents allows for recovery with a single prescription. Yet some physicians still label it a "Seven-Day Syndrome." Initially, Gan Mao (Common Cold) may present with alternating chills and fever, which these physicians misdiagnose as incipient malaria, frequently prescribing Chai Hu (Bupleuri Radix) to force its development into malaria. They fail to realize that Chai Hu (Bupleuri Radix) is specific to the Shaoyang (Lesser Yang) meridian, whereas early-stage Gan Mao (Common Cold) does not involve the Shaoyang (Lesser Yang) meridian. Using Chai Hu (Bupleuri Radix) unjustly attacks healthy Qi, potentially prolonging the Gan Mao (Common Cold). Worse still, some physicians equate Gan Mao (Common Cold) with Shi Xie (Seasonal Pathogenic Factors) and prescribe Dayuan Yin (Reach the Origin Decoction) from *Wen Yi Lun* (Treatise on Pestilential Diseases). If ineffective, they resort to purgative methods, harming patients without remorse, which is truly lamentable.
*Wen Yi Lun* (Treatise on Pestilential Diseases) was written by Wu Youke, a figure from the late Ming Dynasty. During his time, continuous wars and famines caused widespread displacement, with millions dying in ditches. The qi of corpses transformed into pestilential qi, spreading through the world. Those infected suffered household-wide contagion, with infinite transmission potential. While ancient texts occasionally mentioned pestilence, none were dedicated solely to it. Wu Youke correctly identified that pestilential pathogens enter via the mouth and nose and reside in the Membrane Source (Mo Yuan), thus creating Dayuan Yin (Reach the Origin Decoction) and advocating urgent purgation. His methods were effective in that specific context, leading him to write the two-volume *Wen Yi Lun* (Treatise on Pestilential Diseases), offering a novel approach beneficial to medicine. However, his work lacks rigorous detail. Its methods are applicable only during actual pestilence years. Current Shi Xie (Seasonal Pathogenic Factors) are not pestilence; thus, applying these methods is reckless. Treating Shi Xie (Seasonal Pathogenic Factors) as equivalent to pestilence and prescribing Dayuan Yin (Reach the Origin Decoction) initially, repeatedly administering Cao Guo (Tsaoko Fructus) and Hou Po (Magnolia Bark), leads to unbearable dryness-heat. Subsequently, Da Huang (Rhei Radix et Rhizoma) is used for purgation. Survivors are credited, while deaths are blamed on untreatable disease, though the outcome was self-inflicted. The use of Dayuan Yin (Reach the Origin Decoction) for Shi Xie (Seasonal Pathogenic Factors) is inexplicable and strange. Most astonishing is treating fatigue-induced chills and fever as Shi Xie (Seasonal Pathogenic Factors) and administering Dayuan Yin (Reach the Origin Decoction). Fatigue-induced fever is mild; persistent sweating without fever reduction indicates Yin Deficiency. Misdiagnosing this as Shi Xie (Seasonal Pathogenic Factors) obstruction and using Dayuan Yin (Reach the Origin Decoction) violates the prohibition against "treating deficiency as excess," causing harm. I know relatives and friends who suffered from this ignorance, leaving me to sigh in vain. My family members studying medicine must read widely, seek profound principles, avoid relying on simplistic texts, and refrain from rash treatments. Fatigue-induced chills and fevers often resemble exogenous diseases, but differentiation is crucial: the fever is usually mild, decreases upon pressure, and feels lighter; chills are intermittent or variable, relieved by warmth; slight sweating during fever does not reduce it; palm heat exceeds back-of-hand heat; headaches may occur intermittently with varying intensity; although the body feels weary and painful, and spirit is fatigued, consciousness remains clear without delirium. In such cases, regulating Qi and Blood, along with rest, ensures natural recovery. For Yin Deficiency due to fatigue, where sweating fails to reduce fever, herbs like Sheng Di Huang (Rehmanniae Radix) and Dang Gui (Angelicae Sinensis Radix) nourish Yin and clear heat, resolving the fever and illness. Misdiagnosing this as exogenous disease violates the prohibition against "treating deficiency as excess." Further misdiagnosing it as Shi Xie (Seasonal Pathogenic Factors) obstruction and using Dayuan Yin (Reach the Origin Decoison) recklessly is rarely non-fatal.