《脉经》所谓阳附阴、阴附阳者，阴阳谓表里，附谓薄也。阳附阴，即表邪内陷之谓；
阴附阳
，即里邪外乘之谓。病发于太阳则内薄，发于少阴则外薄，薄而不已必争。其与交、并之别
∶交者表里不厘清，附者表多即里少，里多即表少也；并者表并于里即无表，里并于表即无
里，附者里犹带表，表犹带里也。至于争，则薄者将胜矣；将胜者，尽入其境也。表尽入里
则陷，故死；里尽入表则出，故生。阴主阖，阳加之则不能容，故胀满；阳主开，阴加之则
虚者泄，故汗出。而其与并有别者，并者已汗出，附而争者未汗出也。可见诊热病总以汗出
为佳也。又案∶此时胀满，必不大便，下之则其死尤速；此时汗之必昏运；补之则其愈迟，
补甚亦死。一先一后之间，必列此数名，其丁宁示人之意切矣。
《脉经》历集古今众论，其名称或随时代而异，故多有词异旨同者。此谓薄为附，亦其
一端也。
凡脉来盛去微，如人喘状者，是邪气由表薄里之象；若又动数不均，则薄里尤急，即初
大渐
小之厥脉也。伤寒得之为恶寒甚而热多者以此。今病过数日，不见此二脉，知其邪将衰，不
能薄里，不薄里必还表，将汗之兆也。然亦有不薄里又不还表，逗留半表里间而脉如是者，
则象其肺脏之有所载也。肺在躯壳内四脏上，正在半表里之次，邪着于此则脉缓，故去来
平
，初终匀，其人当喑。喑者肺载邪而气实无声也。欲邪之散，仍须从汗出。设汗之不汗，则
邪着固而肺将烂若萎矣，法在不治。《脉经》卷七热病肺不喘三条，义实如此。凡云不者，
皆昨然今否之词，府谓胸中，藏谓胃部，阴阳谓表里，凡云期者，皆施治冀望之词，三日四
日者，自七日后数之也。七加四为十一日，邪气还表，行其经竟之时，至是不汗，则其终不
还表而着肺之固可知，治法乃穷矣。
《脉经》中提到的“阳附阴”和“阴附阳”，其中“阴阳”指的是表里（体表与体内），“附”意为迫近、侵逼。“阳附阴”，即指体表的邪气内陷侵入体内；“阴附阳”，即指体内的邪气向外侵袭体表。病证若发于太阳病（六经病之一，多表现为表证），则邪气向内迫近；若发于少阴病（六经病之一，多表现为里虚寒证），则邪气向外迫近。这种迫近若持续不停，必然发生正邪相争。这与“交”、“并”的区别在于：“交”是指表里界限不清；“附”是指表邪多则里邪少，里邪多则表邪少；“并”是指表邪并入里则无表证，里邪并入表则无里证；而“附”则是里仍带有表证特征，表仍带有里证特征。至于“争”，意味着迫近的一方即将占上风；即将占上风，意味着邪气完全进入对方的领域。如果表邪完全陷入里，即为“陷”，预后不良致死；如果里邪完全透出到表，即为“出”，预后良好可生。阴主闭合，阳邪加之则阴不能容纳，故出现胀满；阳主开泄，阴邪加之则阳气虚弱导致泄泻，故出现汗出。而这与“并”的区别在于，“并”证已经汗出，而“附”且相争的证候尚未汗出。由此可见，诊治热病总以汗出为佳。另外按语：此时出现胀满，必定伴有大便不通，使用下法攻下则死亡更快；此时使用发汗法则必致神志昏乱；使用补法则痊愈缓慢，补益太过也会致死。在一先一后治疗时机的关键之间，必须列出这些名称，其反复叮咛示人的用意十分深切。
《脉经》汇集了古今各种论述，其名称可能随时代不同而变化，因此多有词义不同但主旨相同的情况。这里说“薄”就是“附”，也是其中的一个例子。
凡是脉搏来势强盛而去势微弱，像人喘气的样子，这是邪气由体表迫近体内的征象；如果脉搏又跳动快速且不均匀，则邪气内迫尤为急迫，这就是初起脉大随后渐小至微的厥逆脉象。伤寒病出现这种脉象，表现为恶寒严重而发热较多，原因就在于此。如今患病已过数日，未见到这两种脉象，可知邪气将要衰退，不能内迫入里，不能内迫入里则必然返回体表，这是将要汗出的征兆。然而也有既不内迫入里也不返回体表，逗留于半表半里之间而脉象如此的情况，这对应肺脏有所承载邪气的情况。肺位于躯壳内部四脏之上，正处于半表半里的位置，邪气附着于此则脉象缓和，所以脉搏去来平稳，初起和终末均匀，病人应当声音嘶哑或失音。失音是因为肺承载邪气而气实无声。想要使邪气消散，仍然需要通过汗出解决。假设该出汗却不出汗，则邪气固结而肺将腐烂如枯萎一般，按照医理属于不治之症。《脉经》卷七关于热病肺不喘的三条内容，意义实际上就是这样。凡是说“不”字的，都是表示昨天这样今天否定的词语；“府”指胸中，“藏”指胃部，“阴阳”指表里；凡是说“期”字的，都是施治期望痊愈的词语；“三日”、“四日”是从第七天之后开始计算的。七加四等于十一日，是邪气返回体表、经脉运行完毕的时候，到了这个时候还不汗出，那么它最终不再返回体表而固着于肺就可以知道了，治疗方法也就穷尽了。
The "Yang attaching to Yin" and "Yin attaching to Yang" mentioned in the *Mai Jing* (Pulse Classic) refer to "Yin and Yang" as exterior and interior (Biao and Li), and "attaching" means pressing close or encroaching. "Yang attaching to Yin" refers to pathogenic factors from the exterior sinking inward into the interior; "Yin attaching to Yang" refers to pathogenic factors from the interior invading outward toward the exterior. If a disease originates in Taiyang disease (a syndrome in Six Meridians differentiation, often manifesting as an exterior syndrome), the pathogen presses inward; if it originates in Shaoyin disease (a syndrome often manifesting as interior deficiency-cold), the pathogen presses outward. If this pressing continues without cessation, there will inevitably be a struggle between healthy Qi and pathogenic factors. This differs from "Jiao" (interacting/crossing) and "Bing" (merging): "Jiao" means the boundary between exterior and interior is indistinct; "Fu" (attaching) means if exterior pathogens are more, interior pathogens are less, and if interior pathogens are more, exterior pathogens are less; "Bing" means if exterior pathogens merge into the interior, there is no exterior syndrome, and if interior pathogens merge into the exterior, there is no interior syndrome; whereas "Fu" implies the interior still carries characteristics of the exterior, and the exterior still carries characteristics of the interior. As for "Zheng" (struggle/contend), it indicates that the pressing party is about to gain the upper hand; gaining the upper hand means entering completely into the other's domain. If exterior pathogens sink entirely into the interior, it is called "Xian" (sinking), leading to death; if interior pathogens emerge entirely to the exterior, it is called "Chu" (emerging), leading to survival. Yin governs closure; when Yang pathogen adds to it, Yin cannot contain it, resulting in distension and fullness; Yang governs opening; when Yin pathogen adds to it, deficiency leads to leakage, resulting in sweating. The difference from "Bing" is that in "Bing", sweating has already occurred, whereas in "Fu" with struggle, sweating has not yet occurred. Thus, it can be seen that in diagnosing and treating febrile diseases, sweating is generally considered auspicious. Additionally: At this stage, distension and fullness must be accompanied by constipation; using purgation would accelerate death; using diaphoresis at this time would cause confusion; using tonification would delay recovery, and excessive tonification could also lead to death. Between these sequential treatment opportunities, listing these terms demonstrates the urgent intent to instruct clearly.
The *Mai Jing* collects discussions from ancient and modern times; its terminology may vary with eras, so there are many cases where words differ but the essence is the same. Stating that "Bo" (pressing close) is "Fu" (attaching) is one such example.
Whenever the pulse comes strongly and departs weakly, resembling the breathing of a person panting, this is the image of pathogenic factors pressing from the exterior toward the interior; if the pulse is also rapid and irregular, the internal pressing is even more urgent, which is the Jue pulse starting large and gradually becoming small and minute. In Shanghan (Cold Damage) disease, obtaining this pulse indicates severe aversion to cold and abundant heat. If several days have passed since the onset of illness and neither of these two pulses is seen, it is known that the pathogen is weakening, unable to press inward; unable to press inward, it must return to the exterior, indicating an impending sweat. However, there are cases where the pathogen neither presses inward nor returns to the exterior, lingering between the exterior and interior while presenting such a pulse; this corresponds to the Lung organ carrying the pathogen. The Lung resides within the body cavity above the four other Zang organs, precisely in the position of half-exterior half-interior. When pathogen attaches here, the pulse becomes slow; thus, the pulse goes and comes smoothly, uniform at the beginning and end, and the patient should become aphonic. Aphonia occurs because the Lung carries the pathogen and Qi is excess without sound. To dissipate the pathogen, one must still rely on sweating. If sweating does not occur despite the indication, the pathogen will solidify, and the Lung will rot like withering tissue; according to medical principles, this is untreatable. The three clauses in Volume 7 of the *Mai Jing* regarding febrile disease with non-panting lungs actually convey this meaning. Whenever "bu" (not/no) is used, it signifies a change from past affirmation to present negation; "Fu" refers to the chest center, "Zang" refers to the stomach area, "Yin and Yang" refer to exterior and interior; whenever "qi" (expectation/timeframe) is used, it refers to the hope for cure after treatment; "three days" and "four days" are counted from after the seventh day. Seven plus four equals eleven days, the time when pathogen returns to the exterior and completes its meridian circulation. By this time, if there is no sweat, it is evident that it will ultimately not return to the exterior but remain fixed in the Lung, and therapeutic methods are exhausted.