《难经》曰∶脉不应病，是为死病也。仲景曰∶邪不空见，中必有奸，设有不应，知变
所缘
。二者其义不同。知变所缘者，以其必有所挟之宿疾、所伏之隐疾也。其脉虽不应显见之证
，而仍与隐伏之病相应也，故曰中必有奸。若《难经》直言死病者，是其并无所挟、无所伏
而真不应者也。何也?凡病之应见于脉者，为其邪在于经，搏于正气，正气失其常度，脉遂
失其常形也。若脏气溃败，阴阳失维，升降出入之顺逆迟速；一随邪气之所为，而正气之力
不能与之相搏而相激，其脉往往通畅如常，起伏如常，不见邪气格拒之象，仅微觉指下呆长
，乏于神力而已。此真气已漓，其人必困乏无力，饮食少思，有时又饥，迫欲得食，行动气
喘，面色苍黄，或耳暴聋，或目暴无所见。又有老痰伏结，以及痞块僻在偏隅，不当气血冲
道，气血与之相避，不致相格，而脉自长滑流行者，此迁延不已之痼疾也。故每见阴阳离脱
之人，肾水虚寒，脾阳枯燥，肝风内煽，两尺长缓起伏条畅，此所谓缓临水宫也。指下颇似
充足有余，而圆而无晕，呆而不灵；且或左或右，或寸或关，必有一部稍见沉弱不及，此虚
损久病，及老年气尽，未死前数月必见之。大率多起于冬至，死于春分者，以水枯不能涵木
，其始肝风内灼，其继肝气外脱也。前人谓缓临水宫，弦居土位，同为败脉。据生平所诊，
弦居土位，犹有可以挽回；缓入水宫，未有能济者。岂非以缓为真阴真阳之涣散乎?阴散，
故脉不能紧；阳散，故脉不能洪。不紧、不洪，故似缓也。《难经》又谓∶人病脉不病，虽
困无害。此措词轩轾失当。脉不病者，脉不败也；若病久且困，不能饮食，不能转侧，虽神
识清明，言语不乱，脉来匀滑长缓，亦终于败而已。何者?五脏清枯，故神明不乱；大气孤
行，故脉不变；血络已竭，故身不能动也。故《难经》又谓∶寸口脉平而死者，生气独绝于
内也。至于老痰痼疾，不见于脉者，以其不当气血冲道也，故有患积 而情急欲死者，正当
冲
道也；有发之频数者，迫近冲道也；有宽缓无事者，远于冲道也。前人以此为气血与之相习
，非也。夫果气血相习，是阴阳失维，正气无权矣。
《难经》说：脉象与病症不相符合，这是死证。张仲景说：邪气不会凭空出现，体内必定有奸邪（潜伏的病邪），如果遇到脉症不符的情况，要推究变化的缘由。这两者的含义不同。“推究变化缘由”的意思是，因为患者必定兼有宿疾或潜伏的隐疾。虽然脉象不与表面明显的症状相应，但却与潜伏的疾病相应，所以说“体内必有奸邪”。而《难经》直接说是死证，是指既无兼夹之病，也无潜伏之疾，而是真正的不相符合。为什么呢？凡是疾病在脉象上有所反映，是因为邪气在经络中，搏击正气，导致正气失去常态，脉象也就失去了正常的形态。如果脏气溃败，阴阳失去维系，升降出入的顺逆迟速完全随邪气的摆布，而正气的力量已不能与之搏击激荡，其脉象往往通畅如常，起伏如常，不见邪气格拒的现象，只是微微感觉指下脉形呆滞、长直，缺乏神气罢了。此时真气已经耗散，病人必然困乏无力，饮食减少且思食，有时又感到饥饿，迫切想要进食，行动时气喘吁吁，面色苍黄，或者突然耳聋，或者突然失明。又有老痰伏结，以及痞块偏居一隅，不挡气血运行的通道，气血避开它而不致相互格拒，脉象自然表现为长滑流行，这是迁延不愈的顽固疾病。所以经常见到阴阳离决的人，肾水虚寒，脾阳枯燥，肝风内动，两尺脉长缓、起伏条畅，这就是所谓的“缓脉临水宫”。指下感觉颇为充足有余，但圆钝而无晕感，呆板而不灵动；而且左或右，寸或关，必有一部稍微显得沉弱不及，这是虚损久病，以及老年人元气耗尽，在死亡前几个月必然出现的脉象。大率多起于冬至，死于春分，是因为肾水枯竭不能涵养肝木，起初是肝风在内灼烧，继而是肝气向外脱失。前人认为“缓脉临水宫”和“弦脉居土位”，都是败脉。根据我平生的诊察经验，弦脉居土位，还有可以挽回的可能；缓脉入水宫，没有能救治成功的。这难道不是因为缓脉代表真阴真阳的涣散吗？阴气涣散，所以脉不能紧；阳气涣散，所以脉不能洪。不紧、不洪，所以看起来像缓脉。《难经》又说：人病了但脉象正常，虽然困顿但没有危险。这种措辞轻重失当。所谓“脉不病”，是指脉象未败坏；如果病久且困顿，不能饮食，不能翻身侧卧，虽然神识清明，言语不乱，脉来匀滑长缓，最终也会败坏。为什么呢？五脏精气枯涸，所以神明不乱（意识尚存）；宗气孤行，所以脉象不变；血络已竭，所以身体不能动弹。所以《难经》又说：寸口脉象平和却死亡的，是生机独绝于内。至于老痰痼疾，不在脉象上反映出来的，是因为它不挡气血运行的通道。所以有的患积聚病而情势危急想死的，是因为病邪正当冲道；有的发作频繁的，是因为病邪迫近冲道；有的宽缓无事的，是因为病邪远离冲道。前人把这解释为气血与病邪相习染，是不对的。如果真的是气血与病邪相习染，那就是阴阳失去维系，正气无权了。
The *Nan Jing* (Classic of Difficult Issues) states: When the pulse does not correspond to the disease, it is a sign of a fatal condition. Zhang Zhongjing stated: Pathogenic factors do not appear without cause; there must be hidden pathogenic factors within. If there is a discrepancy between pulse and symptoms, one must understand the origin of the variation. The meanings of these two statements are different. "Understanding the origin of the variation" implies that there must be underlying chronic diseases or latent illnesses. Although the pulse may not correspond to the overtly manifesting symptoms, it still corresponds to the latent disease; hence, it is said that "there must be hidden pathogenic factors." In contrast, when the *Nan Jing* directly refers to a fatal condition, it describes a situation where there are neither concurrent nor latent diseases, but rather a true non-correspondence. Why? Generally, when a disease manifests in the pulse, it is because the pathogen is in the meridians, battling the healthy Qi (Vital Energy), causing the healthy Qi to lose its normal state, and thus the pulse loses its normal form. If the Zang-organ Qi is collapsing and Yin and Yang lose their mutual support, the smoothness or reversal, slowness or speed of ascending, descending, exiting, and entering all follow the whims of the pathogen. At this stage, the power of the healthy Qi is insufficient to battle or stimulate the pathogen. Consequently, the pulse often appears smooth and normal, with regular rising and falling, showing no signs of pathogenic obstruction. It merely feels slightly stiff and long under the fingers, lacking spiritual vitality. At this point, the True Qi has already dissipated. The patient will inevitably feel weak and fatigued, have little appetite yet sometimes feel hungry and urgently desire food, pant upon movement, exhibit a sallow complexion, or suffer from sudden deafness or blindness. Additionally, there are cases of old phlegm stagnation or masses located in peripheral areas, which do not obstruct the main channels of Qi and Blood flow. Since Qi and Blood avoid these masses without clashing, the pulse naturally flows smoothly and rapidly. This represents a chronic, intractable disease. Therefore, it is often observed that in patients with separating Yin and Yang, where Kidney Water is deficient and cold, Spleen Yang is dry and exhausted, and Liver Wind stirs internally, the pulses at both Chi positions are long, slow, and flowing smoothly. This is referred to as "Slow Pulse arriving at the Water Palace." Under the fingers, it may seem abundant and sufficient, but it is round without clarity, stiff without agility. Moreover, whether on the left or right, Cun or Guan position, there is invariably one section that appears slightly deep, weak, and insufficient. This is seen months before death in patients with long-standing deficiency consumptive diseases or in the elderly whose Qi is exhausted. Such conditions generally begin around the Winter Solstice and lead to death around the Spring Equinox, because the dried-up Water cannot nourish Wood. Initially, Liver Wind burns internally; subsequently, Liver Qi escapes externally. Predecessors considered both "Slow Pulse at the Water Palace" and "Wiry Pulse at the Earth Position" as failing pulses. Based on my lifelong diagnostic experience, a Wiry Pulse at the Earth position can sometimes be reversed; however, a Slow Pulse entering the Water Palace has never been successfully treated. Is this not because the Slow Pulse signifies the dispersion of True Yin and True Yang? When Yin disperses, the pulse cannot become Tight; when Yang disperses, the pulse cannot become Full (Hong). Lacking both Tightness and Fullness, it resembles a Slow Pulse. The *Nan Jing* also states: "When a person is diseased but the pulse is normal, although distressed, there is no danger." This wording is imprecise regarding severity. "Pulse not diseased" means the pulse has not failed. If a patient has been ill for a long time, is distressed, unable to eat, and unable to turn over, even if their consciousness is clear and speech is coherent, and the pulse comes evenly, smoothly, long, and slow, it will ultimately fail. Why? Because the essence of the Five Zang organs is dried up, so consciousness remains undisturbed; the Great Qi moves alone, so the pulse remains unchanged; the blood collaterals are exhausted, so the body cannot move. Thus, the *Nan Jing* further states: "When the Cunkou pulse is peaceful but the patient dies, it is because the Source of Life is exclusively severed within." Regarding old phlegm and chronic diseases that do not manifest in the pulse, it is because they do not obstruct the main channels of Qi and Blood. Therefore, some patients with accumulations (Ji Ju) who are in critical condition and near death have their pathology directly in the main channel; others who attack frequently have pathology close to the main channel; those who are stable and asymptomatic have pathology far from the main channel. Predecessors attributed this to Qi and Blood becoming accustomed to the pathogen, which is incorrect. If Qi and Blood were truly accustomed to the pathogen, it would mean Yin and Yang have lost their support and healthy Qi has lost its authority.