《素问·脉要精微论》曰∶“持脉有道，虚静为保。”（切脉之道，贵于精诚，
嫌其扰乱，故必心虚而无他想，身静而不言动，然后可以察脉之微而不失病情也。保者，不失也。若躁
动不安，瞻视不定，轻言谈笑，乱说是非，不惟不能得脉中之巧，适足为旁观者鄙且笑也。）
黄帝曰∶“决死生奈何？”岐伯曰∶“形盛脉细，少气不足以
息者危。（身形肥盛，而脉形细弱，且少气而不足以呼吸，则外有余而
内不足，枝叶盛而根本拔也。故曰，少气不足以息者危。）形瘦脉大，胸中多气者死。
（身形瘦削，而脉形洪大，且胸中多气者，阴不足而阳有余也。孤阳不生，故知必死。）形气相得者生。
（形盛者脉亦盛，形小者脉亦小，则形与脉相得矣。相得者，相合也。）参伍不调者病。（参伍者，数目也。言其
至数不匀，往来无常度，故知必病。）三部九候皆相失者死。（皆相失者，如应浮而沉，应小而大，
违四时之度，失五脏之常者矣。）上下左右之脉相应如参舂者病甚。上下左右相失不可数者死。
（上下左右，即两手之三部九候也。参舂者，实大有力，如杵之舂，故曰病甚。若失其常度，至于急数而
不可数，即八九至之绝脉也，安得不死！）中部之候相减者死。”（
众部虽调，而中部独不及者，为根本败坏，安得生乎！）
《素问·脉要精微论》中说：“诊察脉搏有法则，以心神虚空、身体安静为根本保障。”（切脉的方法，贵在精诚专一，忌讳受到扰乱，所以必须内心虚空没有杂念，身体安静不随意动作，然后才能察觉脉搏的微妙变化而不偏离病情。保，就是不失的意思。如果躁动不安，目光游移不定，轻率言语谈笑，胡乱说是非，不仅不能掌握脉象的精妙之处，反而只会被旁观者鄙视和嘲笑。）
黄帝问：“如何判断死生？”岐伯说：“形体壮盛但脉象细弱，气息短少不足以呼吸的，属于危重证候。（身形肥胖壮实，但脉形细弱，且气短不足以呼吸，这是外表有余而内里不足，如同枝叶茂盛而树根被拔除。所以说，气短不足以呼吸的属于危重证候。）形体消瘦但脉象洪大，胸中气多胀满的，主死。（身形瘦削，但脉形洪大，且胸中感觉气多胀满，这是阴液不足而阳气有余。孤阳无法独存，所以知道必然死亡。）形体与脉象相协调的，主生。（形体壮盛的脉象也壮盛，形体小的脉象也小，这就是形体与脉象相协调。所谓相协调，就是相互契合。）脉象参差错落不调匀的，是病证。（参伍，指数目。意思是脉搏至数不均匀，往来没有常规节律，所以知道必然患病。）三部九候的脉象都失常的，主死。（所谓都失常，比如应该浮取却沉取，应该小脉却见大脉，违背了四季变化的规律，失去了五脏正常的脉象特征。）上下左右各部的脉象相应，像舂米一样坚实有力且节奏不均的，病情严重。上下左右脉象失调且急促到无法计数的，主死。（上下左右，即两手各部分的三部九候。参舂，指脉象实大有力，像木杵舂米一样，所以说是病情严重。如果失去常度，变得急促快速以至于无法计数，就是八九次跳动一次的绝脉，怎么能不死呢！）中部脉象减弱不足的，主死。（其他各部虽然调匀，唯独中部脉象不及，这是根本败坏，怎么能生存呢！）
The *Suwen: Pulse Essentials and Subtle Discussions* states: "There is a method for holding the pulse; emptiness of mind and stillness are the guarantee." (The art of pulse diagnosis values sincerity and precision, avoiding disturbance. Therefore, one must keep the mind empty without distracting thoughts, and remain physically still without unnecessary movement, so as to perceive the subtleties of the pulse without deviating from the true condition of the disease. 'Guarantee' means not losing [the truth]. If one is restless and uneasy, with wandering eyes, speaking lightly and laughing, or gossiping about right and wrong, one will not only fail to grasp the intricacies of the pulse but will also be despised and laughed at by onlookers.)
Yellow Emperor asked: "How do we determine life and death?" Qibo replied: "If the body is robust but the pulse is fine and thin, and there is shortness of breath insufficient for respiration, the condition is critical. (The physique is obese and robust, yet the pulse form is fine and weak, accompanied by shortness of breath insufficient for breathing. This indicates excess on the exterior and deficiency within, akin to lush branches and leaves but uprooted foundations. Thus, it is said that shortness of breath insufficient for respiration indicates a critical condition.) If the body is emaciated but the pulse is洪大 (hongda, large/vigorous), and there is excessive qi in the chest, death ensues. (The physique is lean and wasted, yet the pulse form is large and vigorous, accompanied by a sensation of excessive qi in the chest. This indicates deficiency of Yin and excess of Yang. Solitary Yang cannot generate life alone; thus, death is certain.) If the body and pulse are harmonious, life ensues. (When the body is robust, the pulse is also robust; when the body is small, the pulse is also small. This constitutes harmony between body and pulse. Harmony means mutual accord.) If the pulses are irregular and uncoordinated, disease exists. ('Canwu' refers to numbers. It means the pulse rate is uneven, lacking a consistent rhythm, indicating the presence of disease.) If the pulses in all three positions and nine regions are lost/disordered, death ensues. (Being 'lost' means, for example, a pulse that should be floating is sunken, or one that should be small is large, violating the rhythms of the four seasons and losing the normal characteristics of the five zang organs.) If the pulses above and below, left and right correspond to each other like pounding with a pestle, the disease is severe. If the pulses above and below are disordered and too rapid to count, death ensues. ('Above and below' refers to the three positions and nine regions of both hands. 'Pounding with a pestle' describes a pulse that is full, large, and forceful, like a pestle striking, indicating severe disease. If the normal rhythm is lost, becoming so rapid and numerous that it cannot be counted—such as eight or nine beats per cycle—it is a pulse of extinction; how can survival be expected?) If the pulse in the middle region is diminished, death ensues. (Although other regions may be regular, if the middle region alone is deficient, the foundation is ruined; how can life be sustained?)"