八里为阴（象易少阴之数八），微、沉、缓、涩、迟、伏、濡、弱也。
微脉者，若有若无，极细而软也，多兼于迟，主于阴寒。然或热甚汗泄、
吐、利，气而损虚者；或阳厥极深者，或阳极将死，脉欲绝者；脉亦有微、沉、
缓、涩、迟、伏、濡、弱诸阴脉见也。不寒便言为寒，须以标本明之。
先病为本，根本也；后病为标，梢末。又为病之气为本，受病之脏腑经络为标。世俗至此更不
明其阳极热证，但以执其阴脉为寒，内外急救于于阳，则残阴暴绝，而反致死亡者不少也。且察
色、听声、问证、切脉为神、
圣、功、巧，别病之四法，而脉最为下，则安可执巧之一法，而去其神、圣、功之三法耶！及夫八
里之脉，皆有此义，以微脉居先，故于此总而言之也。
沉脉轻手不见，重切之乃得，动在肌肉之下，其位属阴，为病在里。一名脏
病，或蓄于胸及膀胱者，虽为腑病，其脉亦沉，则皆宜下之。由十二脏腑俱在
里，而经络皆在表也。大抵但以浮为表，沉为里。然虽脏为阴主里，腑为阳主表，其于病脉之浮、沉有所
不拘也。故太阴脾脏之病腹满而脉浮者，桂枝攻于表也。夫脉沉数为里热，沉迟为里寒。余脉皆仿此。
或里热吐、利，气液虚损，或阳厥极深，或热极将死者，亦皆见诸阴脉沉，切宜审之，不可妄以施治。
缓脉者，纵缓而不急，似迟而小疾。缓而迟为寒，缓大长为热。
当伤风自汗，或自汗过多，亦为迟缓，热更甚也。
涩脉者，涩而不滑也。或如刀刮竹，或涩而止住者，涩之太过，主液血衰。
由汗、泄、吐、利，或血溢、血泄，或热盛耗液而成燥也。一曰涩主心痛，血少故也，以心养血。
迟脉者，一息四至以下也。迟为病寒，然热盛自汗，吐利过极，则亦为
迟也。
气液损虚，故脉迟而不能数。
伏脉者，脉附于骨，沉之甚也。伏主水蓄于内，积饮不散也。伏位属阴，在里深也。病之寒热，以随阴阳别之。
附，切近也。水蓄于内，一名留饮。
濡脉者，按之似无，举之无力也，有似微弱，多兼于迟，主于极冷。然热泄
后，或热极将死者，脉亦濡弱，须以外证标本参之。
弱脉者，软虚而无力也。弱之虚冷，必兼微与迟也。然而伤风、中暑，热甚而自汗大出，则易缓弱而迟也。
八里脉属于阴脉（对应《易经》中少阴的数字八），具体包括微、沉、缓、涩、迟、伏、濡、弱这八种脉象。
微脉，感觉若有若无，极其细软，多与迟脉兼见，主要主阴寒证。然而，如果是热邪极盛导致大汗淋漓、呕吐、泄泻，致使气机受损而虚损；或者是阳气厥逆极深；或者是阳极将死、脉气欲绝的情况，也会出现微、沉、缓、涩、迟、伏、濡、弱等诸种阴脉。如果不辨寒热就说是寒证，必须通过辨别标本来说明。先发生的病为本，即根本；后发生的病为标，即梢末。另外，致病的气因为本，受病的脏腑经络为标。世俗之人到了这里更加不明白阳极热证的道理，只是执着于阴脉就认为是寒证，内外急救阳气，结果导致残存的阴气突然断绝，反而造成死亡的案例不少。况且观察面色、听声音、询问症状、切脉被称为神、圣、功、巧四种高超的诊法，是辨别疾病的四种方法，而切脉是最下等的，怎么能只执着于“巧”这一种方法，而抛弃神、圣、功这三种方法呢！至于八里脉，都有这样的含义，因为微脉排在前面，所以在这里总括而言。
沉脉，轻取不见，重按才能摸到，跳动位置在肌肉之下，其部位属阴，表示病在里。一名脏病，或者邪气蓄积在胸及膀胱的，虽然属于腑病，其脉也沉，那么都适宜用下法治疗。因为十二脏腑都在里，而经络都在表。大体上以浮脉为表，沉脉为里。然而虽然脏属阴主里，腑属阳主表，但在病脉的浮、沉表现上有所不拘泥。所以太阴脾脏的病出现腹部胀满而脉浮的，是因为桂枝攻治表邪的缘故。脉沉数表示里有热，脉沉迟表示里有寒。其余脉象都仿照此理推断。如果里有热导致呕吐、泄泻，气液虚损，或者阳气厥逆极深，或者热极将死的，也都出现各种阴脉中的沉脉，务必仔细审察，不可妄加施治。
缓脉，纵缓而不紧急，似迟脉但稍快。缓而迟表示寒，缓大而长表示热。应当见于伤风自汗，或者自汗过多，也表现为迟缓，这是热更甚的表现。
涩脉，涩滞而不滑利。有的像刀刮竹子，或者涩滞而有停顿，涩得太过，主津液血液衰少。由于汗、泄、吐、利，或者血溢、血泄，或者热盛耗伤津液而成燥所致。一说涩脉主心痛，是因为血少，因为心主养血。
迟脉，一呼一吸之间脉搏跳动四次以下。迟脉主寒病，然而热盛自汗，吐利过度，也会表现为迟脉。这是因为气液损伤虚损，所以脉迟而不能数。
伏脉，脉象附着于骨上，比沉脉更深。伏脉主水饮蓄积于内，停饮不散。伏位属阴，在里部深处。病的寒热，随着阴阳不同而区别。附，意为切近。水蓄积于内，一名留饮。
濡脉，按之似乎没有，举之无力，有点像微弱脉，多兼见迟脉，主极冷。然而热泄之后，或者热极将死的，脉也呈现濡弱，必须结合外在证候和标本参合判断。
The "Eight Li" pulses belong to Yin (corresponding to the number of Shaoyin in the I Ching), specifically including the Micro (Wei, 微), Deep (Chen, 沉), Moderate (Huan, 缓), Rough (Se, 涩), Slow (Chi, 迟), Hidden (Fu, 伏), Soft (Ru, 濡), and Weak (Ruo, 弱) pulse types.
The Micro pulse feels as if it is there or not, extremely thin and soft; it often accompanies the Slow pulse and primarily indicates Cold syndrome due to Yin deficiency. However, in cases where excessive heat causes profuse sweating, vomiting, or diarrhea, leading to Qi damage and deficiency; or when Yang collapse is profound; or when Yang extremity approaches death and the pulse is about to vanish, various Yin pulses such as Micro, Deep, Moderate, Rough, Slow, Hidden, Soft, and Weak may also appear. One must not simply label a condition as Cold without distinguishing between Heat and Cold; this requires clarifying the Root (Ben, 本) and Branch (Biao, 标). The initial illness is the Root, i.e., the foundation; the subsequent illness is the Branch, i.e., the extremities. Furthermore, the pathogenic Qi is the Root, while the affected Zang-Fu organs and meridians are the Branch. Laypeople, failing to understand the pathology of Yang extremity Heat syndromes, often cling to the presence of Yin pulses to diagnose Cold, administering emergency warming treatments internally and externally. This can cause residual Yin Qi to abruptly cease, leading to death in many cases. Moreover, observing complexion, listening to voice, asking about symptoms, and palpating the pulse are regarded as the Divine, Sage, Skillful, and Ingenious methods—the four techniques for distinguishing diseases. Among these, pulse diagnosis is considered the lowest tier. How can one rely solely on the "Ingenious" method of pulse diagnosis while abandoning the Divine, Sage, and Skillful methods? The principles regarding the Eight Li pulses apply here generally; since the Micro pulse is listed first, it serves as a summary in this context.
The Deep pulse is not visible with light pressure but is obtained with heavy pressing; its movement lies beneath the muscles, its position belongs to Yin, indicating that the disease is internal (Li, 里). It is also called a Zang disease pulse. Even if the pathogen accumulates in the chest or Bladder—though these are Fu organs—the pulse remains Deep, suggesting that purgative treatment is appropriate. Generally, all twelve Zang-Fu organs reside internally, while the meridians reside externally. Broadly speaking, Floating (Fu, 浮) indicates external (Biao, 表) conditions, and Deep indicates internal conditions. Although Zang organs are Yin and govern the interior, and Fu organs are Yang and govern the exterior, the manifestation of Floating or Deep in pathological pulses is not strictly bound by this rule. For instance, in Taiyin Spleen disease presenting with abdominal fullness and a Floating pulse, it is because Guizhi Tang (Cinnamon Twig Decoction) is targeting the exterior. A Deep and Rapid pulse indicates Internal Heat, while a Deep and Slow pulse indicates Internal Cold. Other pulses follow this logic. In cases of Internal Heat causing vomiting or diarrhea, Qi and fluid depletion, profound Yang collapse, or impending death from extreme heat, various Yin pulses such as Deep may appear; careful examination is essential, and reckless treatment should be avoided.
The Moderate pulse is relaxed and not tense, resembling the Slow pulse but slightly faster. A Moderate and Slow pulse indicates Cold, whereas a Moderate, large, and long pulse indicates Heat. This pattern is seen in Wind-strike with spontaneous sweating, or when spontaneous sweating is excessive, indicating intensified Heat.
The Rough pulse is unsmooth and obstructed. It may feel like a knife scraping bamboo, or it may have pauses. Excessive Roughness indicates depletion of body fluids and blood. This results from sweating, diarrhea, vomiting, or hemorrhage, or from Heat consuming fluids and causing dryness. Some sources state that the Rough pulse relates to Heart pain due to Blood deficiency, as the Heart governs the nourishment of Blood.
The Slow pulse beats fewer than four times per respiration cycle. Slowness typically indicates Cold disease; however, in cases of excessive Heat with sweating, or extreme vomiting and diarrhea, the pulse may also become Slow due to Qi and fluid depletion and deficiency.
The Hidden pulse adheres closely to the bone, being deeper than the Deep pulse. It indicates water retention internally and accumulated fluid stagnation. Its position belongs to Yin and lies deep within the interior. The nature of Cold or Heat in the disease should be distinguished according to Yin and Yang principles. "Adhering" means close proximity. Water retained internally is also known as Retained Fluid (Liu Yin, 留饮).
The Soft pulse seems absent upon pressing and lacks strength upon lifting; it resembles the Micro pulse and often accompanies the Slow pulse, indicating extreme Cold. However, after heat-induced sweating or in cases of impending death from extreme heat, the pulse may also appear Soft and Weak; this must be evaluated by correlating with external signs and the Root-Branch relationship.
The Weak pulse is soft, deficient, and lacking strength. The deficiency and Cold associated with the Weak pulse must accompany the Micro and Slow pulses. However, in cases of Wind-strike or Summerheat, where Heat is severe and accompanied by profuse sweating, the pulse may easily transform into a Moderate, Weak, and Slow pattern.