体象 代为禅代，止有常数；不能自还，良久复动。
代亦歇止之脉。但促、结之止，内有所碍，虽止而不全断，中有还意；代则止而不还，良久复止，如四时之
禅代，不愆其期也。又促、结之止，止无常数；代脉之止，止有定期。
主病 代主藏衰，危恶之候。脾土败坏，吐利为咎。中寒不食，腹疼难救。
止有定期者，盖脾主信也。故《内经》以代脉一见，为藏气衰微，脾气脱绝之诊。
按代脉之义，自各不同。如《素问·宣明五气篇》曰∶“脾脉代。”《灵枢·邪气脏腑病形篇》曰∶“黄者其
脉代。”皆言藏气之常候，非谓代为止也。《素问·平人气象论》曰∶“长夏胃微软弱曰平，但代无胃曰
死”者，盖言无胃气而死，亦非以代为止也。若脾王四季，而随时更代者，乃气候之代，即《宣明五气》
等篇所云者是也。若脉平匀，而忽强忽弱者，乃形体之代，即《宣明五气》等篇所云者是也。脉无定候，
更变不常，则均为之代，须因变察情。如云五十动而不一代者，是乃至数之代。大抵脉来一息五至，则
肺、心、脾、肝、肾五脏之气皆足，故五十动而不一止，合大衍之数，谓之平脉。反此则止乃见焉。肾气不能
至，则四十动一止；肝气不能至，则三十动一止；脾气不能至，则二十动一止；心气不能至，则十动一止；
肺气不能至，则四五动一止。至当自远而近，以次而短，则由肾及肝，由肝及脾，由脾及心，由心及肺。故
凡病将死者，必气促以喘，仅呼于胸中数寸之间。此时真阴绝于下，孤阳浮于上，气短已极，医者犹欲
平之散之，未有不随扑而灭者。戴同父云∶“三部九候，候必满五十动，出自《难经》，而伪诀五脏歌中，
皆以四十五动准，乖于经旨。又云∶‘四十一止一藏绝，却后四年多命没。’荒疵尤甚。夫人岂有一藏既
绝，尚活四年。叔和亦曰∶‘脉来四十动而一止者，一藏无气，却后四岁春草生而死。’未知《灵枢·根
结篇》但言动止之数，以诊五脏无气之候，何尝凿言死期耶？”滑伯仁曰∶“无病而羸瘦、脉代者，危候
也。有病而气血乍损，只为病脉。”此伯仁为暴病者言也。若久病而得代脉，冀其回春，万不得一矣。
伤寒心悸，有中气虚者，停饮者，汗下后者。中气虚则阳陷，阳受气于胸中，阳气陷则不能上充于胸中，
故悸。停饮者，饮水多而停于心下也。水停心下，水气上凌，心不自安，故悸。汗后则里虚矣。况汗乃心液，
心液耗则心虚，心虚故悸。诸悸者，未必皆脉代；若脉代者，正指汗后之悸，以汗为心液，脉为心之合耳。
女胎十月而产，腑脏各输真气资以培养。若至期当养之经虚实不调，则胎孕为之不安，甚则下血而
堕矣。当三月之时，心包络养胎。《灵枢·经脉篇》云∶“心包主脉。”若分气及胎，脉必虚代。在《灵枢·
五脏生成篇》曰∶“心合脉。”盖心与心包，虽分二经，原属一藏故耳。代脉主病，但标脾脏虚衰，而不及
他症，故附列焉。
体象：代脉的特征是更替出现，停止的次数有固定规律；脉搏不能自行恢复，经过较长时间后才再次跳动。
代脉也属于歇止脉的一种。但是促脉、结脉的停止，是因为体内有阻滞，虽然停止但并未完全断绝，中间还有回还之意；而代脉则是停止后不再回还，经过较长时间才再次停止，就像四季的更替一样，不差其时。另外，促脉、结脉的停止没有固定的次数；代脉的停止则有固定的周期。
主病：代脉主要主脏气衰微，是危重恶候。若脾土败坏，会出现呕吐、下利的症状。若是中寒导致不能进食，腹痛难治，则难以挽救。
停止有固定周期的原因，大概是因为脾主信（守信）。所以《内经》认为一见代脉，就是脏气衰微、脾气脱绝的诊断依据。
关于代脉的含义，各家解释各不相同。如《素问·宣明五气篇》说：“脾脉代。”《灵枢·邪气脏腑病形篇》说：“面色黄的人，其脉代。”这都是指脏气的正常征候，并非指代脉为停止之脉。《素问·平人气象论》说：“长夏季节，胃气微软弱称为平脉，如果只有代脉而没有胃气，就是死证。”这说的是没有胃气而死，也不是把代脉当作停止之脉。如果脾旺于四季，随着季节变化而更替，这是气候的更替，即《宣明五气》等篇所说的情况。如果脉象平和均匀，忽然变强忽然变弱，这是形体状态的更替，也是《宣明五气》等篇所说的情况。脉象没有固定征候，变化无常，都称为代，必须根据变化来考察病情。如果说“五十次搏动中有一次不代”，这是至数上的代。大抵脉搏一息跳动五次，则肺、心、脾、肝、肾五脏之气都充足，所以五十次搏动中没有一次停止，符合大衍之数，称为平脉。与此相反，就会出现停止。肾气不足，则四十次搏动停止一次；肝气不足，则三十次搏动停止一次；脾气不足，则二十次搏动停止一次；心气不足，则十次搏动停止一次；肺气不足，则四五次搏动停止一次。这种停止应当是从远到近，依次缩短，即由肾及肝，由肝及脾，由脾及心，由心及肺。所以凡是病将死亡的人，必然气促喘息，仅能在胸中几寸之间呼吸。此时真阴在下枯竭，孤阳在上浮越，气短已至极点，医生还想用平散的方法治疗，没有不随即死亡的。戴同父说：“三部九候诊法，每次必满五十动，出自《难经》，而伪诀中的《五脏歌》都用四十五动为准，违背了经典旨意。又说：‘四十一动一止，一脏气绝，此后四年多命尽。’荒谬错误尤其严重。人岂有一脏气绝还能活四年的道理？叔和也说：‘脉来四十动而一止者，一脏无气，此后四年春草生时而死。’不知《灵枢·根结篇》只是讲动止的数量，用以诊断五脏无气的征候，何曾明确说出死期呢？”滑伯仁说：“无病而身体消瘦、脉见代脉的，是危重征候。有病而气血突然受损的，只是病脉。”这是滑伯仁针对突发疾病而言的。如果是久病而出现代脉，希望其痊愈，万中无一了。
伤寒心悸，有中气虚的，有停饮的，有汗下之后的。中气虚则阳气下陷，阳气受气于胸中，阳气下陷则不能上充于胸中，所以心悸。停饮者，是饮水过多而停滞在心下。水停心下，水气上凌于心，心不安宁，所以心悸。发汗之后则里虚。况且汗是心液，心液耗损则心虚，心虚故悸。各种心悸，未必都有代脉；若见代脉，正是指汗后的心悸，因为汗为心液，脉为心之合应。
女胎十月分娩，脏腑各自输送真气以资培养。如果到了该滋养的时期，经脉虚实不调，则胎孕不安，甚至出血堕胎。在怀孕三个月时，心包络养胎。《灵枢·经脉篇》说：“心包主脉。”如果分气及胎，脉必虚代。在《灵枢·五脏生成篇》说：“心合脉。”大概心和心包，虽然分为两条经脉，原本属于同一脏的缘故。代脉主病，只标出脾脏虚衰，而未涉及其他病症，所以附列于此。
Morphology: The characteristic of Dai pulse (Intermittent Pulse) is its alternation; the pauses occur with a constant number. It cannot return spontaneously, and resumes beating only after a long interval.
Dai pulse also belongs to the category of intermittent pulses. However, in Cu pulse (Rapid Intermittent Pulse) and Jie pulse (Knotted Pulse), the pauses are caused by internal obstructions; although they pause, they do not completely sever, retaining a sense of returning flow. In contrast, Dai pulse pauses without returning, resuming only after a long interval, much like the succession of the four seasons, which never misses its due time. Furthermore, the pauses in Cu and Jie pulses lack a fixed frequency, whereas the pauses in Dai pulse follow a regular cycle.
Pathogenesis: Dai pulse primarily indicates the decline of Zang organ Qi, representing a critical and ominous prognosis. If Spleen Earth fails, it results in vomiting and diarrhea. If Cold invades the Middle causing anorexia and abdominal pain that is difficult to treat, rescue is unlikely.
The reason for pauses having a fixed period lies in the fact that the Spleen governs trustworthiness (regularity). Therefore, the *Nei Jing* (Inner Canon) states that the appearance of Dai pulse is a diagnostic sign of declining Zang Qi and the exhaustion of Spleen Qi.
Regarding the meaning of Dai pulse, interpretations vary. For instance, the *Su Wen · Xuan Ming Wu Qi Pian* states: "The Spleen pulse is Dai." The *Ling Shu · Xie Qi Zang Fu Bing Xing Pian* states: "Those with yellow complexion have a Dai pulse." These refer to the normal manifestations of Zang Qi, not implying that Dai pulse signifies cessation. The *Su Wen · Ping Ren Qi Xiang Lun* states: "In late summer, if the Stomach Qi is soft and weak, it is considered normal; but if there is only Dai pulse without Stomach Qi, it is fatal." This refers to death due to the absence of Stomach Qi, not defining Dai pulse as cessation. When Spleen Qi dominates the four seasons and changes accordingly, this is the succession of climate, as mentioned in the *Xuan Ming Wu Qi* chapter. If the pulse is balanced and uniform but suddenly becomes strong or weak, this is the succession of physical forms, also discussed in those chapters. When pulses lack fixed characteristics and change unpredictably, all are termed Dai, requiring examination of the changing condition. For example, "fifty beats without one Dai" refers to the numerical aspect of Dai. Generally, five beats per breath indicate sufficient Qi in the Lung, Heart, Spleen, Liver, and Kidney. Thus, fifty beats without a pause align with the Great Expansion Number (Da Yan Zhi Shu) and are called Normal Pulse. Conversely, pauses appear. If Kidney Qi is insufficient, there is a pause every forty beats; if Liver Qi is insufficient, every thirty beats; if Spleen Qi is insufficient, every twenty beats; if Heart Qi is insufficient, every ten beats; if Lung Qi is insufficient, every four or five beats. These pauses should progress from distant to near, shortening sequentially: from Kidney to Liver, Liver to Spleen, Spleen to Heart, and Heart to Lung. Therefore, patients nearing death invariably experience rapid breathing and panting, able to breathe only within a few inches of the chest. At this stage, True Yin is exhausted below, and Lone Yang floats above; breathlessness reaches its extreme. If physicians still attempt to treat with dispersing methods, death will inevitably follow. Dai Tongfu stated: "The Three Regions and Nine Positions method requires counting at least fifty beats, originating from the *Nan Jing*. However, the apocryphal *Five Zang Song* uses forty-five beats as standard, deviating from canonical principles. It also claims: 'One pause in forty-one beats indicates one Zang's Qi is exhausted, leading to death after four years.' This is particularly absurd. How can a person survive four years after one Zang's Qi is exhausted? Hehe also said: 'A pause in forty beats indicates one Zang lacks Qi, leading to death when spring grass grows four years later.' Did the *Ling Shu · Gen Jie Pian* explicitly predict death dates? It merely discusses beat counts to diagnose the absence of Zang Qi." Hua Borin stated: "Emaciation with Dai pulse in healthy individuals is a critical sign. In sick individuals with sudden Qi and Blood damage, it is merely a pathological pulse." This refers to acute illnesses. For chronic diseases presenting with Dai pulse, recovery is extremely rare.
In Shang Han (Cold Damage), palpitations may arise from deficiency of Middle Qi, retention of fluid, or post-sweating/purging conditions. Deficiency of Middle Qi causes Yang to sink; since Yang receives Qi in the chest, sinking Yang cannot ascend to fill the chest, causing palpitations. Retention of fluid involves excessive water intake stagnating in the epigastrium. Water stagnation allows Water Qi to harass the Heart, causing insecurity and palpitations. Sweating depletes interior fluids. Since sweat is the fluid of the Heart, depletion leads to Heart deficiency and palpitations. Not all palpitations present with Dai pulse; however, Dai pulse specifically points to palpitations following sweating, as sweat is Heart fluid and the pulse is the manifestation of the Heart.
Female fetuses develop over ten months, nourished by the true Qi transmitted by the Zang-Fu organs. If the meridians responsible for nourishment at term are imbalanced in excess or deficiency, fetal instability occurs, potentially leading to bleeding and miscarriage. During the third month, the Pericardium nourishes the fetus. The *Ling Shu · Jing Mai Pian* states: "The Pericardium governs the vessels." If Qi is shared with the fetus, the pulse must be deficient and intermittent. The *Ling Shu · Wu Zang Sheng Cheng Pian* states: "The Heart combines with the vessels." Although the Heart and Pericardium are distinct meridians, they belong to the same Zang organ. The pathogenesis of Dai pulse highlights Spleen deficiency without mentioning other symptoms, so it is listed here for reference.