病有外因，如六气之风寒暑湿燥热，八方之温热燥寒是也。有内因，如饮食饥饱、喜怒
哀乐、爱恶欲是也。凡此者，皆各有所及之经，有某经之脉象（如寸主阳经，尺主阴经之类），即
有某经之见症（如三阳有头痛，三阴有腹痛之类），且各有所应之脏，有某脏之脉象（心病则
六菽脉洪，肝病则十二菽脉弦之类），即有某脏之见症（心病多笑，肝病多怒之类），此皆确
有
要则固可知也。如见症虽不似初起，总必有一二未除；脉象虽与初起不同，而其可愈、不可
愈总必有胃气可据（脉以和缓为胃气）。此从古圣贤相传要诀，历试不爽者也。病之多门，不
及详论，今专以风门论之。
风为八邪之长，夫人而知之矣。至于伤寒之中风，与偏枯之中风，其所以判然不同之故
，则自晋迄今千百余年，竟无一人道及，可见历来诸家多愦愦也。殊不知出在《灵》、《素》，
特未许浅见窥及耳。夫伤寒之中风，乃六气之风，详在《素问》五营运大论篇，此系四时天
气与宗气相名（宗气即呼吸天气所生，领营血行于脉中者也），其感于人也，必入营中，故初
起必有恶风发热等症，且营血本左右递注，故病则左右俱病，断无偏枯之症。偏枯之中风，
乃八方之风，详见《灵枢》黄帝与岐伯论八风篇中，此是四方贼风与卫气相袭，其入于人也
，但在一隅，而不及营血，故起首无恶风发热等症，且卫气本左右分布，两边各出，故病左
者不及右，病右者不及左，此所以有偏枯之症也。知此则风之源头清矣。再专就八方风论之
。
疾病有外因，如六气（风、寒、暑、湿、燥、热）中的风、寒、暑、湿、燥、热，以及八方（东、南、西、北、东南、西南、东北、西北）的温、热、燥、寒等邪气。也有内因，如饮食的饥饱失调、情绪上的喜怒哀乐、爱憎欲望等。凡是这些病因，都会各自侵犯相应的经络，出现某条经络特有的脉象（例如寸口脉主要反映阳经的情况，尺部脉主要反映阴经的情况），随之就会出现该经络的症状表现（例如三阳经病变多见头痛，三阴经病变多见腹痛等）。并且各脏腑也各有其对应的反应，出现某脏特有的脉象（例如心病时脉搏按之如六粒豆子大小且洪大，肝病时脉搏按之如十二粒豆子大小且弦硬等），随之就会出现该脏的症状表现（例如心病患者多喜笑，肝病患者多易怒等）。这些都是确实存在的规律，原本是可以知晓的。即使症状不像初起时那样典型，总必定有一两项未消除；脉象虽然与初起时不同，但判断其可愈或不可愈，总必须以是否有“胃气”为依据（脉象以和缓从容为有胃气的表现）。这是从古至今圣贤相传的要诀，经过多次验证从未失效。疾病的门类繁多，此处不再详细论述，现在专门针对“风”这一门来进行讨论。
风是八种邪气（八邪）的首领，这是人们所熟知的。至于伤寒病中的“中风”，与偏枯病（半身不遂）中的“中风”，它们之所以截然不同，这个原因从晋代到现在一千多年间，竟然没有一个人提及，可见历来各家医家大多糊涂不清。殊不知这些内容出自《灵枢》和《素问》，只是不允许浅薄的人窥探罢了。所谓伤寒中的“中风”，乃是六气之风，详细记载在《素问·五运行大论》篇中，这涉及四时天气与宗气（宗气即由呼吸自然之气生成，统领营血在脉管中运行的气）的关系，这种邪气侵入人体，必然进入营分，所以初起时一定有恶风、发热等症状。而且营血原本是左右交替循环注流的，所以发病时左右两侧都会受累，绝不会只出现偏枯（半身不遂）的症状。而偏枯中的“中风”，乃是八方之风，详见《灵枢·九宫八风》篇中黄帝与岐伯讨论八风的章节，这是指四面来的贼风侵袭卫气，它侵入人体时，只停留在身体的一个角落，而不波及营血，所以起初没有恶风、发热等症状。而且卫气原本是左右分布的，两边各自向外输布，所以病在左侧就不波及右侧，病在右侧就不波及左侧，这就是为什么会出现偏枯症状的原因。明白了这一点，风的源头就清晰了。再专门就八方之风进行论述。
Diseases have external causes, such as the wind, cold, summer-heat, dampness, dryness, and fire of the Six Qi (Six Climatic Factors), and the warm, hot, dry, and cold from the Eight Directions. They also have internal causes, such as dietary irregularities in hunger and fullness, emotional fluctuations of joy, anger, sorrow, and happiness, and desires of love and aversion. All these factors affect specific meridians, presenting with pulse characteristics of those meridians (e.g., the Cun position primarily reflects Yang meridians, while the Chi position primarily reflects Yin meridians), and consequently manifest symptoms of those meridians (e.g., headache is common in the Three Yang meridians, abdominal pain in the Three Yin meridians). Furthermore, each Zang organ has its corresponding reactions, exhibiting specific pulse patterns (e.g., a heart disease presents with a洪 [Hong] pulse at a depth of six bean-widths; liver disease presents with a弦 [Xian] pulse at a depth of twelve bean-widths) and corresponding symptoms (e.g., heart disease often involves excessive laughter, liver disease often involves irritability). These are established principles that can be understood. Even if symptoms differ from the initial onset, there will invariably be one or two remaining; although the pulse may change from the beginning, the determination of curability or incurability must always rely on the presence of Stomach Qi (a harmonious and moderate pulse indicates the presence of Stomach Qi). This is a crucial secret passed down from ancient sages, proven effective through repeated trials. Due to the multitude of disease categories, they will not be discussed in detail here; instead, we focus specifically on the category of Wind.
Wind is the leader among the Eight Evils (Eight Pathogenic Factors), a fact well known to all. However, the reason why "Zhong Feng" (Stroke/Wind Strike) in Shang Han (Cold Damage) differs fundamentally from "Zhong Feng" in Pian Ku (Hemiplegia) has not been addressed by anyone for over a thousand years since the Jin Dynasty, revealing that many past practitioners were confused. In fact, this knowledge originates from the *Ling Shu* and *Su Wen*, but was perhaps withheld from those with shallow understanding. The "Zhong Feng" in Shang Han refers to the Wind of the Six Qi, detailed in the *Su Wen: Treatise on the Five Movements and Six Operations*. This involves the interaction between seasonal climatic conditions and Zong Qi (Zong Qi is generated by breathing in natural air and guides Ying Blood within the vessels). When this pathogen invades the human body, it enters the Ying (Nutritive) level; therefore, initial symptoms necessarily include aversion to wind and fever. Since Ying Blood circulates alternately from left to right, illness affects both sides simultaneously, making hemiplegia impossible. Conversely, the "Zhong Feng" causing Pian Ku refers to the Wind of the Eight Directions, as detailed in the *Ling Shu: Chapter on the Discussion of Eight Winds between Huangdi and Qibo*. This involves hostile winds from the four directions attacking Wei (Defensive) Qi. Upon invasion, it remains localized in one corner of the body without affecting Ying Blood; thus, initial symptoms do not include aversion to wind or fever. Since Wei Qi distributes bilaterally outwardly, a disease on the left does not affect the right, and vice versa. This explains the occurrence of hemiplegia. Understanding this clarifies the origin of Wind. We shall now discuss the Eight Directional Winds in detail.