《内经》云∶“木郁达之”，古来注释者，以“达”为宣吐；又云∶用柴胡、川芎条而达之。愚谓此不过随文训释，
而于“达之”之意，犹有未尽然也。夫木郁者，即肝郁也。《素问》云∶“治病必求其本。”而郁症之起；必有所因，当求
所因而治之，则郁自解，郁者既解，而达自在其中矣。矧木郁之症，患于妇人者居多，妇人情性偏执，而肝病变幻多端，
总宜从其性，适其宜，而致中和，即为达道。彼若吐、若升，止可以言实，未可以言虚也。今人柔脆者恒多，岂可概施
升吐哉？其余火、土、金、水四郁，古人之注释，虽于《经》义未必有悖，然亦止可以言实，止可以言外因，未可以言
虚，未可以言内因也。盖因郁致疾，不特外感六淫，而于情志为更多。调治之法，亦当求其所因而治之，则郁自解，郁
者既解，则发、夺、泄、折俱在其中矣。因者病之本，本之为言根也、源也，“君于务本，本立而道生，”可师也。
按时病之后，多有发颐毒之症，然古人又有云遗毒者，愚谓当以此“遗”字为正。盖遗者，遗留也，谓余邪未尽，
遗于经络，以致荣气不从，逆于肉理，乃生痈肿也。颐者，但以部位相近而言也。然今之患者，发于耳下为多，两颐甚
少。按耳下者，少阳之部也，三阳以少阳为枢，是余邪从枢而出也。两颐者，少阴之部也，三阴以少阴为枢，是亦余邪
从枢而出也。病在三阳，发于耳下，病在三阴，发于两颐，此一定之理也。张石顽云∶过用发散，引邪泛滥，而颐毒多
有延及膺胁肘臂如流注者，则去颐益远，尚可谓之颐毒乎？
《黄帝内经》中说：“木郁达之”，古来的注释者，把“达”解释为宣发和催吐；又说：使用柴胡、川芎来疏通条达它。我认为这不过是顺着文意进行训诂解释，对于“达之”的深层含义，还有未能完全阐发的地方。所谓木郁，就是肝气郁结。《素问》说：“治病必须探求根本。”而郁证的产生，必定有其原因，应当探究其病因并针对病因治疗，那么郁结自然就会解除，郁结既然解除了，所谓的“达”也就包含在其中了。况且木郁的病症，在女性患者中居多，女性的性情往往偏执，而肝脏病变变幻多端，总宜顺应其性情，使其适宜，从而达到中和的状态，这就是通达之道。那些采用吐法、升提法，只适用于实证，不适用于虚证。现在身体柔弱脆弱的人很多，难道可以一概施用升提和催吐之法吗？其余火、土、金、水四种郁证，古人的注释，虽然未必违背《内经》的原义，但也只适用于实证，只适用于外因，不适用于虚证，不适用于内因。大概因为郁结导致疾病，不仅仅是外感六淫邪气，而在情志致病方面更多见。调治的方法，也应当探求其病因并针对病因治疗，那么郁结自然就会解除，郁结既然解除了，那么发汗、攻夺、泄热、折损等治法也就都包含在其中了。病因是疾病的根本，“本”这个字的意思是根源、源头，“君子致力于根本，根本确立了，道就产生了”，这是值得效法的准则。
按照时令病的规律，其后常伴有发颐毒的病症，然而古人又有称为“遗毒”的说法，我认为应当以这个“遗”字为正解。所谓“遗”，就是遗留的意思，指余邪未尽，遗留于经络之中，导致营气运行不畅，逆乱于肌肉纹理之间，从而产生痈肿。“颐”字，只是以发病部位相近而言罢了。然而现在的患者，多在耳下发作，两颊（颐）很少发作。考察耳下部位，属于少阳经所主区域，三阳经中以少阳为枢纽，这是余邪从枢纽而出。两颊部位，属于少阴经所主区域，三阴经中以少阴为枢纽，这也是余邪从枢纽而出。病在三阳经，发作于耳下；病在三阴经，发作于两颊，这是一定的道理。张石顽说：过度使用发散药物，引致邪气泛滥，而颐毒多有蔓延至胸膺、胁肋、肘部、手臂如同流注病那样的，这就离颐部的范围很远了，还能称之为颐毒吗？
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "For Wood stagnation, promote its free flow." Ancient commentators have interpreted "promote" (Da) as venting and emesis; they also stated that using Chaihu (Bupleuri Radix) and Chuanxiong (Ligustici Chuanxiong Rhizoma) can achieve this promotion. I believe this is merely an exegesis following the text, and it does not fully elucidate the true meaning of "promoting its free flow." What is referred to as Wood stagnation is Liver Qi stagnation. The *Suwen* (Basic Questions) states: "In treating diseases, one must seek the root cause." The onset of stagnation syndromes always has a specific cause; one should investigate the cause and treat accordingly, then the stagnation will naturally resolve. Once the stagnation is resolved, the concept of "promotion" is inherently included therein. Moreover, Wood stagnation syndromes occur more frequently in women. Women's dispositions are often rigid or biased, and Liver pathologies are manifold and changeable. It is generally appropriate to accord with their nature, make them suitable, and achieve harmony and neutrality (Zhonghe), which constitutes the Way of free flow. Methods such as emesis or ascending are applicable only to Excess patterns, not to Deficiency patterns. Nowadays, there are many people with delicate and fragile constitutions; how can one indiscriminately apply ascending and emetic methods? Regarding the other four types of stagnation—Fire, Earth, Metal, and Water—the ancient commentaries may not necessarily contradict the canonical meaning, but they too apply only to Excess patterns and external causes, not to Deficiency patterns or internal causes. Generally, diseases caused by stagnation arise not only from the external contraction of the Six Evils (Liuyin) but are even more frequently due to emotional factors. The method of regulation and treatment should also involve seeking the cause and treating it; thus, the stagnation will naturally resolve. Once the stagnation is resolved, methods such as diaphoresis (Fa), purgation/depletion (Duo), draining (Xie), and restraining/reducing (Zhe) are all encompassed within it. The cause is the root of the disease; the term "root" implies source or origin. As stated, "The gentleman strives for the root; when the root is established, the Way arises," this is a principle worthy of emulation.
Following seasonal diseases, there are often cases of facial swelling/toxins (Fayi Du). However, ancients also referred to this as "lingering toxin" (Yi Du). I believe the character "lingering" (Yi) is the correct interpretation. "Lingering" means remaining behind; it refers to residual pathogens that have not been completely cleared, lingering in the meridians, causing Ying (Nutritive) Qi to fail to follow its proper course and reversing into the muscle tissue, thereby generating carbuncles and swellings. The term "Yi" (cheek/jaw) is used merely because the location is similar. However, in current patients, the condition occurs mostly below the ears, while occurring rarely on both cheeks (Yi). Examining the area below the ear, it belongs to the Shaoyang (Lesser Yang) region. Among the Three Yang meridians, Shaoyang serves as the pivot; thus, the residual pathogens exit via this pivot. The two cheeks belong to the Shaoyin (Lesser Yin) region. Among the Three Yin meridians, Shaoyin serves as the pivot; thus, the residual pathogens also exit via this pivot. When the disease is in the Three Yang meridians, it manifests below the ears; when the disease is in the Three Yin meridians, it manifests on the two cheeks. This is a fixed principle. Zhang Shiweng stated: "Overuse of dispersing agents draws pathogens into rampant spread, and facial toxins often extend to the chest, hypochondrium, elbow, and arm, resembling flowing abscesses (Liuzhu). In such cases, the pathology is far removed from the Yi (cheek); can it still be called facial toxin?"