《素问·六微旨大论》∶“出入废则神机化灭，升降息则气立孤危。”尝谓《伤寒》所论传经，即是出入精义，盖正气
之出入，由厥阴而少阴、而太阴、而少阳、阳明以至太阳，循环往复。六淫之邪，则从太阳入，一步反归一步，至厥阴
而极，此邪气进而正气退行，不复与外气相通。令韶张氏谓之逆传，养葵赵氏谓之郁证，即此义也。故开、阖、枢三者，
乃其要旨。夫分言之，为出入，为升降，合言之，总不外乎一气而已矣。观东垣《脾胃论》浮沉补泻之图，以卯酉为道
路，而归重于苍天之气。考其所订诸方，用升、柴、苓、泽等法，实即发源于长沙论中葛根、柴胡、五苓之意以引而伸
之，所谓升之九天之上，降之九地之下，虽内伤外感殊科，而于气之升降出入，则总无以异耳。王氏曰∶凡窍横者，皆
有出入往来之气，窍竖者，皆有阴阳升降之气，盖人在气中，如鱼在水中，人不见气，如鱼不见水，上下九窍，外而八
万四千毛孔，皆其门户也，气为之充周而布KT ，虽有大风苛毒，莫之能害。是故“邪之所凑，其气必
虚”，内陷者，有入而无出，下陷者，有降而无升，此升降出入四字，为一生之橐 ，百病之纲领。
详考《伤寒论》中寸口之紧与趺阳之紧，虽同曰紧，而义自各别。盖紧见于寸口，是客邪所致之病。脉紧见于趺阳，
趺阳是胃之本脉。《平脉篇》云∶“跌阳脉微而紧，紧则为寒”，又云∶“跌阳脉沉而数，沉为实，数消谷，紧者，病难治。”
夫紧则为寒，数则为热，既曰数，又曰紧，不几寒热混淆欤！卢予繇疏云∶紧则为寒，为其嫌于无阳，盖此寒字非寒邪
之寒，针对阳字而言，乃是形容无阳意思。无阳者，无胃脘之阳也，即所云知阴常在，绝不见阳意。知阴常在绝不见阳，
以尺脉言是肾阳，此以趺阳言是胃阳。人以胃气为本，故诊趺阳须知迟缓，诊寸口当求濡弱，皆胃阳敷布之象，即《经》
文“无胃气曰死”之要旨耳。至于寸口脉浮而紧，寸口脉阴阳俱紧，此紧字以寒邪言。细参之，要自有濡弱者在，所谓
“濡弱何以反适十一头”，为五脏六腑之主，脉之骨也，不得与跌阳之紧混同而论。
《素问·六微旨大论》中说：“如果出入的功能废弛，那么生命活动的内在机制就会消亡；如果升降的运动停止，那么依赖外界环境生存的气机就会陷入孤立危险的境地。”我曾经认为，《伤寒论》中讨论的传经规律，正是出入这一精微义理的体现。大概正气的出入，是从厥阴经开始，经过少阴经、太阴经、少阳经、阳明经，最终到达太阳经，循环往复。而六淫（风、寒、暑、湿、燥、火六种外感病邪）之邪气，则是从太阳经侵入，每一步都逆向退回一步，直到厥阴经达到极点。这是邪气进逼而正气退却，不再与外界之气相通。令韶张氏称之为逆传，养葵赵氏称之为郁证，其含义就是如此。所以开、阖、枢这三者，是其中的关键要旨。分开来说，称为出入，称为升降；合起来说，总归不外乎一气罢了。观察李东垣《脾胃论》中关于浮沉补泻的图示，以卯酉为道路，而归重于苍天之气。考察他所制定的各种方剂，使用升麻、柴胡、茯苓、泽泻等方法，实际上就是发源于长沙（指张仲景）论述中的葛根、柴胡、五苓散的意思并加以引申发挥。所谓“升之九天之上，降之九地之下”，虽然内伤和外感属于不同的类别，但在气的升降出入方面，则总体上没有差异。王氏说：凡是横向的孔窍，都有出入往来的气；竖向的孔窍，都有阴阳升降的气。大概人处在气中，就像鱼在水中，人看不见气，就像鱼看不见水。上下的九窍，以及体外的八万四千毛孔，都是气的门户，气在其中周流充盛并布散全身，即使有大风苛毒，也不能伤害人体。因此，“邪之所凑，其气必虚”，内陷的病证，是有入而无出；下陷的病证，是有降而无升。这“升降出入”四个字，是一生的根本橐龠（比喻气机运行的枢纽），也是百病的纲领。
详细考证《伤寒论》中寸口脉的紧脉与趺阳脉的紧脉，虽然都称为紧脉，但含义自然各自不同。大概紧脉出现在寸口，是由客邪（外来邪气）引起的疾病。紧脉出现在趺阳脉，趺阳脉是胃的本脉。《平脉篇》说：“跌阳脉微而紧，紧则为寒”，又说：“跌阳脉沉而数，沉为实，数能消谷，紧的话，病难治。”紧脉代表寒，数脉代表热，既然说是数脉，又说是紧脉，岂不是寒热混淆了吗？卢予繇在疏解中说：紧则为寒，是因为担心被误解为没有阳气。这里的“寒”字并非指寒邪的寒，而是针对“阳”字而言，乃是形容无阳的意思。无阳，是指没有胃脘的阳气，也就是所说的“知阴常在，绝不见阳”的意思。知道阴气常在，绝对见不到阳气，如果是从尺脉来说，指的是肾阳；这里从趺阳脉来说，指的是胃阳。人以胃气为本，所以诊察趺阳脉应当知道迟缓之象，诊察寸口脉应当寻求濡弱之象，这都是胃阳敷布的表现，也就是《内经》中“无胃气曰死”的要旨罢了。至于寸口脉浮而紧，寸口脉阴阳俱紧，这个“紧”字是指寒邪。仔细参详，其中必然包含有濡弱的脉象在里面，这就是所谓的“濡弱何以反适十一头”，作为五脏六腑的主宰，脉的骨架，不能与趺阳脉的紧脉混同而论。
The *Suwen: Treatise on the Six Micro Principles* states: "If exit and entry cease, the spirit mechanism perishes; if ascent and descent halt, qi standing becomes isolated and perilous." I have often remarked that the discussion of meridian transmission in the *Shanghan Lun* (Treatise on Cold Damage) embodies the profound essence of exit and entry. Generally, the exit and entry of righteous qi proceed from Jueyin to Shaoyin, then Taiyin, Shaoyang, Yangming, and finally to Taiyang, cycling repeatedly. In contrast, pathogenic factors of the six excesses (wind, cold, summerheat, dampness, dryness, fire) enter via the Taiyang channel, retreating step by step until they reach Jueyin as their extreme. This represents the advance of pathogenic qi and the retreat of righteous qi, no longer communicating with external qi. Ling Shao Zhang referred to this as "reverse transmission," while Yang Kui Zhao called it "depression syndrome"; both terms convey this same meaning. Thus, opening, closing, and pivoting constitute the key principles. Discussed separately, they are termed exit/entry and ascent/descent; discussed collectively, they ultimately amount to nothing more than one qi. Observing Li Dongyuan's diagram of floating/sinking and tonifying/reducing in his *Pi Wei Lun* (Treatise on the Spleen and Stomach), which uses Mao and You as pathways and emphasizes the qi of the vast heaven, we can examine his prescribed formulas. Methods using Shengma (Cimicifugae Rhizoma), Chaihu (Bupleuri Radix), Lingpi (Poria), and Zexie (Alismatis Rhizoma) actually originate from the concepts of Gegen (Puerariae Lobatae Radix), Chaihu, and Wuling San (Five-Ingredient Powder with Poria) discussed by Changsha (Zhang Zhongjing), extended and elaborated upon. It is said, "Ascend to the highest heavens, descend to the deepest earth." Although internal injury and external contraction belong to different categories, regarding the ascent, descent, exit, and entry of qi, there is essentially no difference. Master Wang stated: "All orifices oriented horizontally possess qi of exit, entry, and mutual flow; all orifices oriented vertically possess qi of yin/yang ascent and descent." Essentially, humans exist within qi just as fish exist within water; humans cannot see qi, just as fish cannot see water. The nine orifices above and below, along with the eighty-four thousand pores outside, serve as its gates. Qi circulates and distributes throughout the body, so that even severe wind or toxic pathogens cannot cause harm. Therefore, "Where pathogenic factors gather, righteous qi must be deficient." Diseases sinking inward involve entry without exit; diseases sinking downward involve descent without ascent. These four characters—ascension, descent, exit, and entry—are the bellows (tuo yue) of life and the general outline of all diseases.
A detailed examination of the tight pulse at the Cun Kou (radial artery at the wrist) and the tight pulse at the Fu Yang (dorsalis pedis artery) in the *Shanghan Lun* reveals that although both are termed "tight," their meanings differ. A tight pulse appearing at Cun Kou indicates a disease caused by exogenous pathogens. A tight pulse appearing at the Fu Yang pulse, which is the primary pulse of the stomach, requires specific interpretation. The *Ping Mai Pian* (Chapter on Pulse Diagnosis) states: "If the Dizhong pulse is faint and tight, tightness indicates cold." It also states: "If the Dizhong pulse is deep and rapid, deepness indicates excess, rapidity consumes grain, but if tight, the disease is difficult to treat." Tightness indicates cold, and rapidity indicates heat. If it is described as rapid and also as tight, does this not confuse cold and heat? Lu Youyou, in his commentary, explained: "Tightness indicates cold" because one might fear it implies a lack of yang. Here, the character "cold" does not refer to cold pathogenic factors, but rather contrasts with the character "yang," describing the state of lacking yang. Lacking yang means lacking the yang of the epigastrium, which corresponds to the saying, "Knowing that yin remains constant, never seeing yang." Referring to the Chi pulse (wrist position), this denotes kidney yang; referring here to the Fu Yang pulse, it denotes stomach yang. Humans rely on stomach qi as their foundation. Therefore, when diagnosing the Fu Yang pulse, one should recognize the slow and moderate qualities; when diagnosing the Cun Kou pulse, one should seek the soft and weak qualities. Both are manifestations of stomach yang distributing throughout the body, aligning with the essential principle in the Classics: "Absence of stomach qi signifies death." As for the Cun Kou pulse being floating and tight, or the Cun Kou pulse showing tightness in both yin and yang positions, this "tightness" refers to cold pathogenic factors. Upon careful analysis, there must inherently be soft and weak qualities present. This corresponds to the saying, "How can soft and weak [pulses] correspond to the eleven heads?" Serving as the master of the five zang and six fu organs, and the framework of the pulses, this condition must not be conflated with the tightness of the Fu Yang pulse.