疾则呼吸之间脉七八至。凡动滑洪数，
皆属疾类。不似洪脉之既大且数，却无燥疾之形也。疾似亢阳无制，亦有寒热阴阳真假之异。若果疾兼洪大
而坚，是明真阴垂绝，阳极难遏。如系按之不鼓，又为阴邪炎威虚阳发露之征。然要皆属难治，盖疾而
洪大者苦烦满，疾而沉数者苦腹痛，皆为阴阳告绝。惟暴厥暴惊脉见急数，俟平稍愈为无碍耳。其有脉惟
见疾而不大不细，则病虽困可治。（东垣治伤寒脉疾，面赤目赤，烦渴引饮而不能咽，用姜附人参汗之而愈。
守真治伤寒蓄热阳厥，脉疾至七八至以上，用黄连解毒治之而安。）
细则往来如发，而指下显然。凡弱小微濡，皆属细类。不似微脉之微弱模糊也。（语出张璐。又濒湖体
状诗曰∶细来累累细如丝，应指沉沉无绝期；春夏少年俱不利，秋冬老弱却相宜。）细为阳气衰弱之候。然细
亦有分别，如细而兼浮，则为阳气衰弱；细而兼沉，则为寒气内中，或热传三阴；细而兼缓，则为湿中于内。
皆当求其所因，不可混同施治。但脉既细如发，便属气虚，纵有内热，亦当兼固中气，不可纯用解热，以致其
细益甚耳。况有内热全无，真元素亏，神气不持，而致脉见细象者乎。（李士材曰∶尝见虚损之人脉细身热，
医不究原，而以凉剂投之，使真阳散败，饮食不进，上呕下泄，是速其毙耳。经曰∶少火生气。人非此火，无
以营运三焦，熟腐水谷。未彻乎此者，乌可以言医哉。然虚劳之脉，细数不可并见，并见者必死。细则气衰，
数则血败，气血交穷，短期将至。）
疾脉是指在一呼一吸之间，脉搏跳动七到八次的脉象。凡是动滑洪数这几种脉象，都属于疾脉的类别。它们不像洪脉那样既宽大又快速，也没有那种燥急疾速的形态。疾脉看似阳气亢盛而无制约，但也存在寒热、阴阳真假的不同情况。如果确实出现疾脉兼见洪大且坚硬的特征，这是真阴即将枯竭、阳极难以遏制的明证。如果是按之无力不鼓指，则是阴邪炽盛、虚阳外浮显露的征象。然而这些情况大多属于难治之症。一般来说，疾脉兼洪大的患者苦于烦闷胀满；疾脉兼沉数的患者苦于腹痛，这些都是阴阳之气即将绝灭的表现。只有突然昏厥或突然受惊时出现的急数脉象，待病情平稳稍有好转后便无大碍。如果有脉象仅表现为疾快而不大也不细，那么即使病情严重也是可以治疗的。（李东垣治疗伤寒脉疾，患者面赤目赤，烦躁口渴想喝水却咽不下去，用姜附人参汤发汗而痊愈。朱守真治疗伤寒蓄热导致的阳厥，脉疾达到七八次以上，用黄连解毒汤治疗而安定。）
细脉往来如头发丝般细微，但在指下感觉清晰明显。凡是弱小微濡这几种脉象，都属于细脉的类别。它们不像微脉那样微弱模糊。（这段话出自张璐。另外李时珍在《濒湖脉学》体状诗中说：细脉来时累累不绝细如丝线，应指沉沉没有断绝的时候；春夏季节对少年人不利，秋冬季节对老人和弱者却适宜。）细脉是阳气衰弱的征候。但是细脉也有区别，比如细脉兼见浮象，就是阳气衰弱；细脉兼见沉象，就是寒气内侵，或者热邪传入三阴经；细脉兼见缓象，就是湿气内侵。这些都应当探究其病因，不可混淆施治。只要脉象细如发丝，就属于气虚，纵然有内热，也应当兼顾固护中气，不可单纯使用清热药，以免使脉细更加严重。何况还有体内完全没有热邪，而是真元元素亏损，神气不能维持，而导致脉象呈现细象的情况呢？（李士材说：我曾见过虚损之人脉细身热，医生不追究根本原因，而投以凉剂，导致真阳散败，饮食不进，上吐下泻，这是加速其死亡。经文说：少火生气。人如果没有这股火，就无法营运三焦，熟腐水谷。未能透彻理解这一点的人，怎么可以谈论医学呢？然而虚劳病的脉象，细脉和数脉不可同时出现，同时出现的一定要死。细脉代表气衰，数脉代表血败，气血交相穷尽，死期将至。）
The Ji (Rapid) pulse is characterized by seven to eight beats per respiration cycle. All pulses such as Dong (Agitated), Hua (Slippery), Hong (Surging), and Shu (Rapid) belong to the category of Ji. Unlike the Hong pulse, which is both large and rapid, the Ji pulse lacks the form of dryness and urgency. The Ji pulse appears as hyperactive Yang without restraint, yet there are differences regarding true and false manifestations of cold-heat and Yin-Yang. If the Ji pulse is indeed accompanied by a Surging, large, and firm quality, it clearly indicates that True Yin is on the verge of exhaustion and extreme Yang is difficult to restrain. If the pulse feels non-elevating upon deep pressure, it is a sign of flourishing Yin pathogen with the exposure of deficient Yang. However, all these conditions are considered difficult to treat. Generally, patients with a Ji pulse accompanied by Surging and large qualities suffer from vexation and fullness; those with a Ji pulse accompanied by Deep and Rapid qualities suffer from abdominal pain; both indicate the impending extinction of Yin and Yang. Only in cases of sudden syncope or sudden fright where an urgent and rapid pulse appears, provided the condition stabilizes and improves slightly, is there no major concern. If the pulse presents only as rapid without being large or thin, although the illness is severe, it is treatable. (Li Dongyuan treated exogenous febrile disease with a Ji pulse, red face and eyes, vexation, thirst with desire to drink but inability to swallow, using Ginger and Aconite with Ginseng to induce sweating, resulting in recovery. Zhu Shouzhen treated exogenous febrile disease with accumulated heat causing Yang reversal, where the pulse was Ji reaching seven to eight beats or more, using Huanglian Jiedu Decoction to achieve stability.)
The Xi (Fine) pulse comes and goes like a hair, appearing clearly under the fingers. All pulses such as Ruo (Weak), Xiao (Small), Wei (Minute), and Ru (Soggy) belong to the category of Xi. They do not resemble the Wei pulse, which is weak and blurred. (This passage is attributed to Zhang Lu. Additionally, Li Shizhen's poem in Binhu Maixue states: "The Fine pulse comes continuously, thin as silk, sinking under the finger without ever ceasing; unfavorable for youths in Spring and Summer, yet suitable for the elderly and weak in Autumn and Winter.") The Xi pulse is a sign of declining Yang Qi. However, the Xi pulse has distinctions: if Xi is accompanied by Floating, it indicates declining Yang Qi; if Xi is accompanied by Deep, it indicates internal invasion of Cold pathogen or Heat transmitting to the Three Yin meridians; if Xi is accompanied by Slow, it indicates internal invasion of Dampness. In all cases, one must seek the underlying cause and not apply treatment indiscriminately. Once the pulse is fine as a hair, it belongs to Qi deficiency. Even if there is internal heat, one must simultaneously consolidate Middle Qi and cannot purely use heat-clearing methods, lest the pulse become even finer. Furthermore, what about cases where there is absolutely no internal heat, but rather a deficiency of True Yuan elements, with Shen Qi unable to maintain itself, leading to a Xi pulse? (Li Shicai said: "I have seen patients with deficiency consumption presenting with a Fine pulse and body heat. Physicians who did not investigate the root cause administered cooling agents, causing the dispersion and collapse of True Yang, loss of appetite, vomiting above and diarrhea below, thereby hastening their death. The Classic says: 'Lesser Fire generates Qi.' Without this fire, humans cannot circulate the San Jiao and ripen and transform water and grain. Those who do not thoroughly understand this, how can they speak of medicine? However, in consumptive diseases, the Fine and Rapid pulses should not appear together; if they do, death is certain. The Fine pulse signifies Qi decline, the Rapid pulse signifies Blood deterioration. When Qi and Blood are mutually exhausted, the short term [of life] is approaching.")