阳气通行，温养百骸。阳气壅闭，郁而为热。且夫人身之火，无处不有，无时不
在，但喜通达耳。不论脏腑经络，表里上下，血分气分，一有所阻，即便发热，是知百病发
热，皆由于壅郁。然火郁而又根于气，气常灵而火不灵，火不能自运，赖气为之运，所以气升
火亦升，气降火亦降，气行火亦行，气若阻滞，而火屈曲，惟是屈曲热斯发矣，是气为火之舟楫也。
今疫邪透出于膜原，气为之阻，时欲到胃，是求伸而未能遽达也。今投寒剂，抑遏胃气，气
益不伸，火更屈曲，所以反热也。往往服芩、连、知、柏之类，病患自觉反热，其间偶有灵
变者，但言我非黄连证，亦不知其何故也。切谓医家终以寒凉清热，热不能清，竟置弗疑，服之反热，
全然不悟，虽至白首，终不究心，悲夫！
邪之着人，如饮酒然。凡人醉酒，脉必洪而数，气高身热，面目俱赤，乃其常也
。及言其变，各有不同∶有醉后妄言妄动，醒后全然不知者；有虽沉醉而神思终不乱者；醉
后应面赤而反刮白者；应痿弱而反刚强者；应壮热而反恶寒战栗者；有易醉而易醒者；有
难醉
而难醒者；有发呵欠及嚏喷者；有头眩眼花及头痛者。因其气血虚实之不同，脏腑禀赋之各
异，更兼过饮少饮之别，考其情状，各自不同，至论醉酒一也，及醒一时诸态如失。
凡人受
邪，始则昼夜发热，日晡益甚，头疼身痛，舌上白苔，渐加烦渴，乃众人之常也。及言其变
，各自不同者，或呕，或吐，或咽喉干燥，或痰涎涌甚，或纯纯发热，或发热而兼凛凛，或先
凛凛而后发热，或先恶寒而后发热，或先一日恶寒而后发热，以后即纯纯发热；或先恶寒而后发热，以后渐渐寒少而热
多，以至纯热者，或昼夜发热者，或但
潮热，余时热稍缓者。有从外解者∶或战汗，或狂汗、自汗、盗汗、或发斑；有潜消者；有从
内传者∶或胸膈痞闷，或心腹胀满，或心痛腹痛，或胸胁痛，或大便不通，或前后癃闭，或
协热下利，或热结旁流。有黄苔黑苔者，有口燥舌裂者，有舌生芒刺、舌色紫赤者，有鼻孔
如烟煤之黑者，有发黄及蓄血、吐血、衄血、大小便血、汗血、嗽血、齿衄血，有发颐疙瘩
疮者，有首尾能食者，有绝谷一两月者，有无故最善反复者，有愈后渐加饮食如旧者，有愈后
饮食胜常二三倍者，有愈后退爪脱发者
。至论恶证，口噤不能张，昏迷不识人，足屈不能伸，唇口不住牵动，手足不住振战，直视
，上视，圆睁，目瞑，口张，声哑，舌强，遗尿，遗粪，项强发痉，手足俱痉，筋惕肉 ，
循衣摸床，撮空理线等证，种种不同，因其气血虚实之不同，脏腑禀赋之有异，更兼感重感轻
之别，考其证候，各自不同，至论受邪则一也，及邪尽一任诸症如失。所谓知其一万事毕，
知其要者一言而终，不知其要者流散无穷，此之谓也。
以上止举一气，因人而变。至有岁气稍有不同者，有其年众人皆从自汗而解者，更有其年众
人
皆从战汗而解者，此又因气而变，余证大同小异，皆疫气也。至又杂气为病，一气自成一病
，每病各又因人而变。统而言之，其变不可胜言矣，医者能通其变，方为尽善。
阳气在体内通行，温煦滋养全身骨骼形体。若阳气壅滞闭阻，郁结而化生热邪。况且人体内的火（生理之火），无处不有，无时不在，只是喜欢通达顺畅罢了。不论是在脏腑、经络，还是表里、上下，亦或是血分、气分，只要有一处受阻，就会立即发热，由此可知，各种疾病引起的发热，都是由于壅滞郁结所致。然而，火的郁结根源在于气，气机通常灵动而火性相对静止，火不能自行运转，依赖气的推动才能运行，所以气上升火也随之上升，气下降火也随之下降，气运行火也随其运行；如果气机阻滞，火便屈曲不畅，只有当火屈曲不通时，热邪才会发作，这就是说气是火的舟船和渡具。
如今疫邪从膜原透发出来，气机因此受到阻碍，病势时常想要到达胃部，这是正气寻求伸展却未能迅速达到的表现。此时若投用寒凉药物，会抑制遏止胃气，导致气机更加无法伸展，火势更加屈曲，所以反而出现发热加剧的现象。往往有人服用黄芩、黄连、知母、黄柏等寒凉药物后，病患自觉身体反而更热，其中偶尔有灵变的情况，病人只说自己不是黄连证，也不明白其中的缘故。我认为医生们始终坚持以寒凉药清热，结果热不能清，竟然毫不怀疑地继续服用，导致服药后反而发热，全然没有醒悟，即使到了白发苍苍的老年，终究不去深究原因，真是可悲啊！
邪气侵袭人体，就像人喝酒一样。大凡醉酒的人，脉象必定洪大而数急，呼吸急促身体发热，面目都发红，这是正常情况。至于谈到其变化，则各不相同：有的醉酒后胡言乱语、妄动，醒来后完全不知道；有的虽然沉醉但神志思维始终不乱；有的醉后应该面红反而面色苍白；有的应该肢体痿弱反而变得刚强有力；有的应该壮热反而恶寒战栗；有的容易醉也容易醒；有的难醉也难醒；有的打呵欠和打喷嚏；有的头晕眼花和头痛。因为每个人气血虚实不同，脏腑禀赋各异，再加上饮酒多少的区别，考察其情状，各自不同，但归结到醉酒这一件事上，等到酒醒之后，各种状态瞬间消失。
大凡人感受邪气，开始的时候昼夜发热，傍晚时分加重，头疼身痛，舌上有白苔，逐渐出现烦躁口渴，这是众人的普遍情况。至于谈到其变化，则各自不同：有的呕吐，有的吐痰涎，有的咽喉干燥，有的痰涎涌盛，有的纯粹发热，有的发热兼有凛凛怕冷，有的先凛凛怕冷而后发热，有的先恶寒而后发热，有的提前一天恶寒而后发热，之后即纯粹发热；有的先恶寒而后发热，之后渐渐寒少而热多，以至变成纯热证的；有的昼夜发热的；有的只是潮热，其余时间热势稍缓的。有的从体表解除的：有的战汗，有的狂汗、自汗、盗汗、或发斑疹；有的潜消于无形；有的从内部传变的：有的胸膈痞闷，有的心腹胀满，有的心痛腹痛，有的胸胁痛，有的大便不通，有的大小便闭塞不通，有的协热下利，有的热结旁流。有的出现黄苔黑苔，有的口燥舌裂，有的舌生芒刺、舌色紫赤，有的鼻孔像烟煤一样黑，有的发黄及蓄血、吐血、衄血、大小便出血、汗血、咳血、齿龈出血，有的发颐部生疮疙瘩，有的从头到尾都能进食，有的绝食一两个月，有的无故最善于反复无常，有的痊愈后逐渐饮食恢复正常，有的痊愈后饮食超过平常两三倍，有的痊愈后脚趾甲脱落头发脱落。至于谈到危重证候，有的口噤不能张开，昏迷不识人，足部蜷曲不能伸直，嘴唇口角不住牵动，手足不住震颤，眼睛直视，向上翻白眼，圆睁双眼，闭目不语，张口喘促，声音嘶哑，舌体僵硬，遗尿，遗粪，项背强直发生痉病，手足全部痉挛，筋肉跳动，循衣摸床，撮空理线等证候，种种不同，因为每个人气血虚实不同，脏腑禀赋有异，再加上感受邪气轻重之别，考察其证候，各自不同，但归结到感受邪气这一件事上，等到邪气尽除之后，任凭各种症状如失般消失。所谓“知其一万事毕”，掌握关键要点者一言而终，不知关键要点者流散无穷，说的就是这个道理。
以上只列举了一种气（疫气），因人而发生变化。至于有岁气稍有不同的年份，有的年份众人皆通过自汗而解，更有有的年份众人皆通过战汗而解，这又是因岁气而变化，其余证候大同小异，都是疫气所致。至于又杂气致病，一种气自成一种病，每种病又各因人而异发生变化。统而言之，其变化不可胜数，医生若能通晓这些变化，才算尽善尽美。
Yang Qi circulates, warming and nourishing the entire body. When Yang Qi is stagnant and obstructed, it becomes constrained and generates heat. Moreover, the fire within the human body exists everywhere and at all times, but it prefers to be unobstructed and flowing freely. Regardless of whether it is in the Zang-Fu organs or meridians, exterior or interior, upper or lower, blood level or Qi level, if there is any obstruction, fever immediately ensues. Thus, we know that fever arising from various diseases is all due to stagnation and constraint. However, the constraint of fire originates from Qi. Qi is usually agile, whereas fire is relatively static; fire cannot move itself but relies on Qi to transport it. Therefore, when Qi ascends, fire also ascends; when Qi descends, fire also descends; when Qi moves, fire also moves. If Qi becomes obstructed, fire becomes constrained and twisted; only when fire is constrained and twisted does heat manifest. This indicates that Qi serves as the boat and ferry for fire.
Currently, the epidemic pathogen emerges from the Membrane Source (Mo Yuan), causing an obstruction in Qi mechanism. The pathogenic trend often seeks to reach the Stomach, representing a desire for extension that has not yet been rapidly achieved. At this time, administering cold-natured medicines suppresses and inhibits Stomach Qi, causing Qi to become even more unable to extend, and fire becomes even more constrained. Consequently, fever aggravates instead of subsiding. Often, patients take herbs such as Scutellariae Radix (Huangqin), Coptidis Rhizoma (Huanglian), Anemarrhenae Rhizoma (Zhimu), and Phellodendri Cortex (Huangbai), and patients feel their heat intensifies. Occasionally, there are unique variations where patients merely state they do not have a Huanglian syndrome, without understanding the cause. I believe that physicians persistently use cold and cool herbs to clear heat, yet the heat remains uncleared. They continue to administer them without doubt, resulting in aggravated fever after ingestion, completely failing to realize this. Even until old age with white hair, they never investigate the reason, which is truly sorrowful!
The invasion of pathogens into the human body is like drinking alcohol. Generally, a drunk person’s pulse must be surging and rapid, breathing is elevated, the body is hot, and the face and eyes are red; this is the normal state. Regarding its variations, they differ: some speak and act wildly while drunk but know nothing upon waking; some remain mentally clear despite deep intoxication; some should have red faces but appear pale instead; some should be flaccid but become rigid instead; some should have high fever but experience chills and trembling instead; some get drunk easily and wake up easily; some get drunk with difficulty and wake up with difficulty; some yawn and sneeze; some suffer from dizziness, blurred vision, and headache. Due to differences in Qi and Blood deficiency/excess and individual organ constitution, combined with varying amounts of alcohol consumed, their conditions vary. However, regarding drunkenness itself, once sober, all states vanish instantly.
When a person contracts a pathogen, initially there is fever day and night, worsening towards sunset, accompanied by headache and body pain, a white coating on the tongue, gradually progressing to irritability and thirst; this is common among many. Regarding variations, they differ individually: some vomit, some expectorate phlegm, some have dry throats, some have excessive phlegm secretion, some have pure fever, some have fever accompanied by chills, some have chills first then fever, some have aversion to cold first then fever, some have aversion to cold one day prior to fever, followed by pure fever; some have aversion to cold then fever, gradually having less cold and more heat until becoming pure heat; some have fever day and night; some have tidal fever with slight relief otherwise. Some resolve from the exterior: some through shivering sweat, some through manic sweat, spontaneous sweating, night sweating, or eruption of macules. Some dissipate imperceptibly. Some transmit internally: some have chest and diaphragm fullness/stuffiness, some have abdominal distension/pain, some have heart or abdominal pain, some have chest and hypochondriac pain, some have constipation, some have urinary and fecal retention, some have diarrhea with heat, some have heat binding with paralogical flow. Some have yellow or black tongue coatings, some have dry mouth and cracked tongue, some have prickles on the tongue with purple-red color, some have nostrils black like soot, some have jaundice and blood stasis, hematemesis, epistaxis, hematochezia/melena, hematohidrosis, hemoptysis, gingival bleeding, some have parotid swelling/sores, some can eat from start to finish, some fast for one or two months, some exhibit frequent relapses, some recover appetite gradually post-recovery, some have increased appetite 2-3 times normal post-recovery, some lose toenails and hair post-recovery. Regarding severe syndromes: trismus with inability to open mouth, coma with loss of consciousness, flexed legs unable to extend, twitching lips and mouth, tremors of hands and feet, fixed gaze, upward rolling of eyes, wide-open eyes, closed eyes without speech, gaping mouth, hoarseness, stiff tongue, enuresis, encopresis, neck stiffness with spasms, spasm of hands and feet, muscle twitching, grasping at clothes and bed threads, picking at empty air, etc. These vary greatly due to differences in Qi/Blood status, organ constitution, and pathogen severity. However, regarding contracting the pathogen, once the pathogen is exhausted, all symptoms vanish. As stated, "Knowing the one principle ends all matters"; those who grasp the essence conclude with one word, while those who miss the essence scatter infinitely. This is what is meant.
The above only lists one type of Qi (epidemic Qi), varying according to the individual. In years where the annual Qi differs slightly, some years everyone resolves via spontaneous sweating, others via shivering sweat; this varies due to annual Qi, with other syndromes being largely similar, all caused by epidemic Qi. Furthermore, miscellaneous Qi causes disease; one Qi forms one disease, and each disease varies by individual. Generally speaking, the variations are countless. A physician who can comprehend these variations achieves perfection.