内经曰感虚乃陷下也
谨按针经曰陷下则灸之夫病有邪气陷下正气陷下者也然经谓邪气陷下者是经虚气少邪入
故曰
感虚乃陷下也故诸邪陷下在经者宜灸之正气陷下者若东垣所谓饮食劳倦内伤元气胃脘之阳不
能升举并心肺之气陷入于中焦药以扶持元气胃气是也然用药亦有轻重轻者用升浮之剂如补中
益气汤益胃升阳汤之类是也重者宜用劫剂来复丹灵砂丹之类是也沉诸邪陷下宜灸之证亦有标
本不同论见寒门方后
谨按人禀冲和之气而生身有三曰元精曰元气曰元神者本身中之真精真气真脉也夫精乃腑
脏之
真非荣血之比故曰天癸气乃腑脏之大经为动静之主故曰神机脉为天真委和之一气经谓其名有
三曰命之本气之神形之道其机运升降皆随气而
动因血而荣精气资始相生不失以养一身为人之司命形质之体用也至若精不足则气失资化气不
足则血失所营血不足则气无所附天真散乱则气血精神无所禀命矣是以相生长养之道精化气气
生神而皆禀乎身中脏腑之真也夫气血从乎荣卫荣卫又宗乎经隧荣卫者精气之化为先天清浊之
始经隧者胃之水谷气化此经隧不能不生荣卫荣卫不能不散而养经脉经脉不能不顺而资天真为
生养涵容造化形质理之然也凡人之视听言动壮寿皆此理之常也疾病盲 关格夭折皆此理之失
也故有精神气血不足则病真脉散乱则死者皆由平日摄养之过与不及动止之不逾常度也经云出
入废则神机化灭升降息则气立孤危然房劳甚则精血竭而神无所根据气无所附则忽致暴绝也窃尝
第究先哲经义济生微旨益气之补肺补精之滋肾皆滋其化源也盖人之精血而常不足加之数夺其
真资化失则荣气乃虚虚则卫气不固精亦滑夺肾气竭而阴微不能与胃气上升以接清阳之气故病
多头重或痛气弱而食少元气下陷脉即微弱外散欲绝而虚洪或见损脉此实元精不足之所致非有
外感贼邪之病也
《内经》说：感受虚邪，就会导致气机陷下。
谨按：《针经》说：气机陷下的病证应当用灸法治疗。然而疾病中有邪气陷下和正气陷下两种情况。但经文所说的“邪气陷下”，是因为经脉虚弱、气少，导致邪气侵入，所以说“感受虚邪才会导致陷下”。因此，凡是邪气陷在经脉中的，适宜用灸法治疗。至于正气陷下，就像李东垣所说的饮食劳倦内伤元气，胃脘之阳不能升举，并伴有心肺之气陷入中焦，用药应当扶持元气和胃气。然而用药也有轻重之分：轻症使用升浮的方剂，如补中益气汤、益胃升阳汤之类；重症则适宜使用劫剂，如来复丹、灵砂丹之类。沉伏的邪气陷下适宜用灸法治疗，这些证候也有标本的不同，论述详见寒门方后。
谨按：人禀受冲和之气而生，身体有三宝：元精、元气、元神，这是人身中的真精、真气、真脉。精是脏腑的真精，不同于营血，所以说它是天癸之源；气是脏腑的大经，作为动静的主宰，所以说它是神机所在；脉是天真委和的一股气。经文说它的名字有三种：命之本、气之神、形之道。其机能运行升降都随气而动，因血而荣养。精气资始相生，不失时机以滋养全身，是人的司命，是形质的体用关系。如果精不足，则气失去资生转化的基础；气不足，则血失去所营养的对象；血不足，则气无所依附；天真散乱，则气血精神无所禀受命令。所以相生长养的规律是：精化气，气生神，且都禀受于身中脏腑的真气。气血遵循营卫的运行，营卫又宗奉于经隧。营卫是精气化为先天清浊的开始，经隧则是胃的水谷气化之所。因为经隧不能不产生营卫，营卫不能不散布以滋养经脉，经脉不能不顺遂以资助天真，从而为生养涵容造化，这是形质道理的自然结果。大凡人的视听言动、壮年长寿，都是这个道理的正常表现；疾病、盲聋、关格、夭折，都是这个道理的失常所致。所以有精神气血不足则生病，真脉散乱则死亡的，这都是由于平日摄养的过错与不及，以及动静举止不逾常度造成的。经文说：“出入废则神机化灭，升降息则气立孤危。”然而房事过度则精血枯竭，神无所根据，气无所依附，就会忽然导致暴绝。我曾探究先哲的经义和济生的微旨，认为益气的补肺、补精的滋肾，都是滋生化之源。大概人的精血本来就常常不足，加上多次掠夺其真元，资生转化失序，则营气乃虚，虚则卫气不固，精亦滑脱耗夺，肾气竭而阴微，不能与胃气上升以接引清阳之气，所以病见头重或痛，气弱而食少，元气下陷，脉即微弱外散欲绝，或者出现虚洪或损脉，这实际上是元精不足所致，并非有外感贼邪的疾病。
The *Neijing* states: "When affected by deficiency, sinking and collapse occur."
According to the *Zhenjing*: "For conditions of sinking and collapse, moxibustion should be applied." However, in disease, there are cases of pathogenic factor sinking/collapse and cases of healthy qi sinking/collapse. Yet, when the classics refer to "pathogenic factor sinking/collapse," it is because the meridians are deficient and qi is scanty, allowing pathogens to enter; hence it is said, "Only when affected by deficiency does sinking/collapse occur." Therefore, for all cases where pathogens sink into the meridians, moxibustation is appropriate. Regarding healthy qi sinking/collapse, as described by Li Dongyuan, internal injury from diet and overwork damages the Yuan Qi (Original Qi), causing the Yang of the stomach region to fail to ascend, accompanied by the Heart and Lung Qi sinking into the Middle Jiao. Medicinal treatment should support the Yuan Qi and Stomach Qi. However, medication also varies in intensity: for mild cases, ascending and floating formulas are used, such as Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) or Yiwei Shengyang Tang (Benefit the Stomach and Raise the Yang Decoction); for severe cases, potent "robbery" agents (strong corrective formulas) like Laifu Dan (Return to Life Pill) or Lingsha Dan (Cinnabar Pill) are appropriate. For deeply seated pathogenic sinking, moxibustation is indicated. These syndromes also differ in their root and branch aspects; discussions can be found after the formulas in the Cold Gate section.
According to my understanding: Humans are born endowed with the harmonious Qi. The body possesses three treasures: Yuan Jing (Original Essence), Yuan Qi (Original Qi), and Yuan Shen (Original Spirit), which are the true essence, true qi, and true pulse within the person. Essence is the true essence of the Zang-Fu organs, distinct from Ying Blood (Nutritive Blood); thus it is said to be the source of Tian Gui (Heavenly Water). Qi is the great channel of the Zang-Fu organs, serving as the master of movement and stillness; thus it is said to be the locus of Shen Ji (Spirit Mechanism). The Pulse is a single breath of Tian Zhen Wei He (Innocent Harmony). The classics state its names are threefold: the Root of Life, the Spirit of Qi, and the Path of Form. Its mechanisms of operation, ascent, and descent move with Qi and nourish through Blood. Essence and Qi originate and generate each other without loss, nourishing the whole body; they are the life governors of humans and the substance and function of physical form. If Essence is insufficient, Qi loses its basis for transformation; if Qi is insufficient, Blood loses its nourishment; if Blood is insufficient, Qi has no attachment; if Tian Zhen scatters and disorders, then Qi, Blood, Essence, and Spirit have no command to rely upon. Thus, the way of mutual growth and nourishment is: Essence transforms into Qi, Qi generates Shen, and all are endowed with the true Qi of the internal Zang-Fu organs. Qi and Blood follow the circulation of Ying and Wei (Defensive) Qi; Ying and Wei Qi, in turn, rely on the Jing Sui (Meridian Vessels). Ying and Wei Qi represent the beginning of the transformation of essence into the primordial clear and turbid states; Jing Sui vessels are where the Qi transformation of water and grain from the Stomach occurs. Because Jing Sui must produce Ying and Wei Qi, and Ying and Wei Qi must disperse to nourish the meridians, and the meridians must flow smoothly to assist Tian Zhen, thereby generating, nourishing, containing, and creating transformations—this is the natural principle of physical form. Generally, human vision, hearing, speech, movement, vigor, and longevity are normal manifestations of this principle; diseases, blindness/deafness, Guan Ge (Obstruction and Reversal), and premature death are deviations from this principle. Therefore, insufficiency of Spirit, Essence, Qi, and Blood leads to illness; scattering and disorder of the True Pulse leads to death. All these result from errors and excesses in daily self-care, and movements that do not adhere to regular measures. The classics say: "If exit and entry cease, the Shen Ji (Spirit Mechanism) perishes; if ascent and descent stop, the Qi Li (Qi Establishment) stands alone in danger." However, excessive sexual activity depletes Essence and Blood, leaving Shen without foundation and Qi without attachment, leading suddenly to violent cessation of life. I have studied the scriptural meanings of ancient sages and the subtle principles of saving lives, concluding that tonifying the Lung to benefit Qi and nourishing the Kidney to supplement Essence both aim to nourish the source of transformation. Essentially, human Essence and Blood are often inherently insufficient; compounded by frequent depletion of one's true resources, if the basis for transformation is lost, Ying Qi becomes deficient. Deficiency leads to insecure Wei Qi, sliding and depletion of Essence, exhaustion of Kidney Qi, and Yin weakness. Unable to ascend with Stomach Qi to connect with Clear Yang Qi, symptoms such as heavy head or pain arise. Qi is weak with poor appetite; Yuan Qi sinks; the pulse becomes weak, scattered, and nearly imperceptible, or appears falsely surging or damaged. This is actually caused by insufficiency of Yuan Jing (Original Essence), not by diseases caused by external thieving pathogens.