九难曰∶何以别知脏腑之病耶？然∶数者腑也，迟者脏也。数则为热，迟则为寒。诸阳为热，
诸阴为寒，故以别知脏腑之病也。
十难曰∶一脉为十变者，何谓也？然∶五邪刚柔相逢之意也。假令心脉急甚者，肝邪干心也；
心脉微急者，胆邪干小肠也∶心脉大甚者，心邪自干心也；心脉微
大者，小肠邪自干小肠也。心脉缓甚者，脾邪干心也；心脉微缓者，胃邪干小肠也。心脉涩甚者，肺邪
干心也；心脉微涩者，大肠邪干小肠也。心脉沉甚者，肾邪干心也；心脉微沉者，膀胱邪干小肠也。五
脏各有刚柔邪，故令一脉辄变为十也。
十一难曰∶经言脉不满五十动而一止，一脏无气者，何脏也？然∶人吸者随阴入，呼者因阳出。今吸
不能至肾，至肝而还，故知一脏无气者，肾气先尽也。
十二难曰∶经言五脏脉已绝于内，用针者反实其外∶五脏脉已绝于外，用针者反实其内。内外之绝
，何以别之？然∶五脏脉已绝于内者，肾肝气已绝于内也，而医反补其心肺；五脏脉已绝于外者，其心
肺脉已绝于外也，而医反补其肾肝。阳绝补阴，阴绝补阳，是谓实实虚虚，损不足益有余，如此死者，
医杀之耳。
十三难曰∶经言见其色而不得其脉，反得相胜之脉者即死；得相生之脉者，病即自已。色之与脉
当参相应，为之奈何？
然∶五脏有五色，皆见于面，亦当与寸口尺内相应。假令色青，其脉当弦而急；色赤，其脉浮大而
散；色黄，其脉中缓而大；色白，其脉浮涩而短；色黑，其脉沉濡而滑。此所谓五色之与脉，当参相应也。
脉数，尺之皮肤亦数；脉急，尺之皮肤亦急；脉缓。尺之皮肤亦缓；脉涩，尺之皮肤亦涩，脉滑，
尺之皮肤亦滑。
五脏各有声色臭味，当与寸口尺内相应，其不应者病也，假令色青，其脉浮涩而短，若大而缓
为相胜；浮大而散，若小而滑为相生也。
经言知一为下工，知二为中工，知三为上工。上工者十全九，中工者十全七，下工者十全六。此
之谓也。
第九难说：怎样辨别和知晓脏腑的疾病呢？回答说：脉数（脉搏跳动快速）属于腑，脉迟（脉搏跳动缓慢）属于脏。脉数表示有热证，脉迟表示有寒证。诸阳经主热，诸阴经主寒，所以通过脉象的迟数可以辨别和知晓是脏病还是腑病。
第十难说：一脉象呈现十种变化，这是什么意思呢？回答说：这是五邪（风、寒、暑、湿、燥/火等致病因素）中刚柔相克、相互侵犯的意思。例如，心脉急（紧张如按琴弦）严重的，是肝邪侵犯心脏；心脉微急的，是胆邪侵犯小肠；心脉大（宽大有力）严重的，是心邪自犯心脏；心脉微大的，是小肠邪自犯小肠；心脉缓（松弛缓慢）严重的，是脾邪侵犯心脏；心脉微缓的，是胃邪侵犯小肠；心脉涩（往来艰涩不畅）严重的，是肺邪侵犯心脏；心脉微涩的，是大肠邪侵犯小肠；心脉沉（轻取不应，重按始得）严重的，是肾邪侵犯心脏；心脉微沉的，是膀胱邪侵犯小肠。五脏各有刚柔之邪相互侵犯，所以使得一脉象往往能变为十种变化。
第十一难说：医经上说，脉搏不满五十次就出现一次歇止，说明有一脏无气了，是哪一脏无气呢？回答说：人吸气时，气随阴经深入体内；呼气时，气因阳经出于体外。现在吸气不能到达肾脏，吸到肝脏就返回来了，所以知道有一脏无气的，是肾气先耗尽。
第十二难说：医经上说，五脏脉象在内部已经绝灭，使用针刺的人反而充实其外部；五脏脉象在外部已经绝灭，使用针刺的人反而充实其内部。内部的绝灭和外部的绝灭，怎样来辨别呢？回答说：五脏脉象在内部已经绝灭的，是肾气和肝气在内部已经绝灭，而医生反而补益心肺；五脏脉象在外部已经绝灭的，是心脉和肺脉在外部已经绝灭，而医生反而补益肾肝。阳气绝灭却去补阴，阴气绝灭却去补阳，这叫做“实实虚虚”（使实证更实，虚证更虚），损害不足的正气，增加有余的邪气，像这样导致死亡的，是医生杀死了病人。
第十三难说：医经上说，看到病人的面色却得不到相应的脉象，反而得到相克（相胜）的脉象就会死亡；得到相生脉象的，疾病就会自行痊愈。面色与脉象应当参合相应，该怎么做呢？
回答说：五脏对应五色，都显现于面部，也应当与寸口尺内的脉象相应。例如，面色青，脉象应当弦（端直以长）而急；面色赤，脉象应当浮大而散；面色黄，脉象应当中和缓而大；面色白，脉象应当浮涩而短；面色黑，脉象应当沉濡而滑。这就是所说的五色与脉象应当参合相应。
脉数，尺部（前臂内侧靠近手腕处）的皮肤也感觉发热躁动；脉急，尺部的皮肤也感觉紧张；脉缓，尺部的皮肤也感觉松弛；脉涩，尺部的皮肤也感觉粗糙不平；脉滑，尺部的皮肤也感觉光滑润泽。
五脏各有声、色、臭、味，应当与寸口尺内的脉象相应，如果不相应就是有病。例如，面色青，脉象应当弦急，如果见到浮涩而短的脉，或者是大而缓的脉，这是相克（相胜）的关系；如果见到浮大而散的脉，或者是小而滑的脉，这是相生的关系。
医经上说，只知其一的为下工（低水平的医生），知其二的为中工（中等水平的医生），知其三的上工（高水平的医生）。上工的治愈率十分之九，中工的治愈率十分之七，下工的治愈率十分之六。说的就是这个道理。
Difficulty 9 states: How can one distinguish and know the diseases of the Zang (Yin) and Fu (Yang) organs? The answer is: A rapid pulse (Shu Mai, 数脉) belongs to the Fu organs, while a slow pulse (Chi Mai, 迟脉) belongs to the Zang organs. A rapid pulse indicates Heat, and a slow pulse indicates Cold. All Yang meridians are associated with Heat, and all Yin meridians are associated with Cold; thus, by distinguishing these, one can identify whether the disease resides in the Zang or Fu organs.
Difficulty 10 states: What is meant by "one pulse transforming into ten variations"? The answer is: This refers to the interaction of Gang (Yang/Hard) and Rou (Yin/Soft) pathogens among the Five Evils (Wu Xie, 五邪). For example, if the Heart pulse is severely tense (Ji Mai, 急脉), it indicates Liver Evil invading the Heart; if the Heart pulse is slightly tense, it indicates Gallbladder Evil invading the Small Intestine. If the Heart pulse is severely large (Da Mai, 大脉), it indicates Heart Evil self-invading the Heart; if slightly large, it indicates Small Intestine Evil self-invading the Small Intestine. If the Heart pulse is severely relaxed/slow (Huan Mai, 缓脉), it indicates Spleen Evil invading the Heart; if slightly relaxed, it indicates Stomach Evil invading the Small Intestine. If the Heart pulse is severely choppy (Se Mai, 涩脉), it indicates Lung Evil invading the Heart; if slightly choppy, it indicates Large Intestine Evil invading the Small Intestine. If the Heart pulse is severely deep (Chen Mai, 沉脉), it indicates Kidney Evil invading the Heart; if slightly deep, it indicates Bladder Evil invading the Small Intestine. Since each of the Five Zang organs has Gang and Rou evils that invade one another, a single pulse position often manifests ten variations.
Difficulty 11 states: The Classics say that if the pulse stops after fewer than fifty beats, it indicates that Qi is absent in one organ. Which organ lacks Qi? The answer is: When inhaling, Qi follows Yin pathways inward; when exhaling, Qi exits via Yang pathways. Currently, inhalation cannot reach the Kidneys but returns upon reaching the Livers. Therefore, knowing that one organ lacks Qi, we conclude that Kidney Qi is exhausted first.
Difficulty 12 states: The Classics say that when the pulses of the Five Zang organs are already extinct internally, practitioners mistakenly tonify the exterior; when the pulses are already extinct externally, they mistakenly tonify the interior. How does one distinguish between internal extinction and external extinction? The answer is: When the pulses of the Five Zang organs are extinct internally, it means Kidney and Liver Qi are extinct internally, yet physicians mistakenly tonify the Heart and Lungs. When the pulses of the Five Zang organs are extinct externally, it means Heart and Lung pulses are extinct externally, yet physicians mistakenly tonify the Kidneys and Livers. Tonifying Yin when Yang is extinct, and tonifying Yang when Yin is extinct, constitutes "making the Excess more Excess and the Deficiency more Deficient" (Shi Shi Xu Xu, 实实虚虚). This damages what is insufficient and augments what is excessive. Death resulting from such actions is effectively murder by the physician.
Difficulty 13 states: The Classics say that if one observes the complexion but fails to find the corresponding pulse, and instead finds a mutually overcoming (Xiang Sheng, 相胜) pulse, death ensues; if a mutually generating (Xiang Sheng, 相生) pulse is found, the disease will resolve spontaneously. How should the complexion and pulse be correlated?
The answer is: The Five Zang organs correspond to five colors, which manifest on the face and should also correspond with the pulses at Cun Kou (Inch Position) and Chi Nei (Cubit Position). For instance, if the complexion is Green (Qing, 青), the pulse should be Tense (Xian Mai, 弦脉) and rapid; if Red (Chi, 赤), the pulse should be Floating (Fu Mai, 浮脉), Large, and Scattered; if Yellow (Huang, 黄), the pulse should be Moderate, Relaxed, and Large; if White (Bai, 白), the pulse should be Floating, Choppy, and Short; if Black (Hei, 黑), the pulse should be Deep (Chen Mai, 沉脉), Soft (Ru Mai, 濡脉), and Slippery (Hua Mai, 滑脉). This is what is meant by the correlation of the five colors and the pulses.
If the pulse is Rapid, the skin at the Chi position is also warm/restless; if the pulse is Tense, the skin at the Chi position is also tight; if the pulse is Relaxed, the skin at the Chi position is also loose; if the pulse is Choppy, the skin at the Chi position is also rough; if the pulse is Slippery, the skin at the Chi position is also smooth.
Each of the Five Zang organs has specific sounds, colors, odors, and tastes that should correspond with the pulses at Cun Kou and Chi Nei. Lack of correspondence indicates disease. For example, if the complexion is Green, the pulse should be Tense and rapid. If a Floating, Choppy, and Short pulse is seen, or a Large and Relaxed pulse, this represents an Overcoming (Ke, 克) relationship. If a Floating, Large, and Scattered pulse, or a Small and Slippery pulse is seen, this represents a Generating (Sheng, 生) relationship.
The Classics state: Knowing only one aspect makes one a Lower-grade practitioner (Xia Gong, 下工); knowing two aspects makes one a Middle-grade practitioner (Zhong Gong, 中工); knowing three aspects makes one an Upper-grade practitioner (Shang Gong, 上工). An Upper-grade practitioner cures nine out of ten cases; a Middle-grade practitioner cures seven out of ten; a Lower-grade practitioner cures six out of ten. This is the principle described here.