四难曰∶脉有阴阳之法，何谓也？然∶呼出心与肺，吸入肾与肝，呼吸之间，脾受谷味也，其
脉在中。浮者阳也，沉者阴也，故曰阴阳也。心肺俱浮，何以别之？然∶浮而大散者心也，浮而短
涩者肺也。肾肝俱沉，
何以别之？然∶牢而长者肝也，按之濡、举指来实者肾也。脾者中州，故其脉在中，是阴阳之法也。
六难曰∶脉有阴盛阳虚，阳盛阴虚，何谓也？然∶浮之损小，沉之实大，故曰阴盛阳虚；沉之
损小，浮之实大，故曰阳盛阴虚，是阴阳虚实之意也。
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。
十四难曰∶上部有脉，下部无脉，其人当吐，不吐者死。上部无脉，下部有脉，虽困无能为害
。所以然者，人之有尺，譬如树之有根，枝叶虽枯槁，根本将自生。脉有根本，人有元气，故知不
死。
问曰∶脉有阴阳，何谓也？答曰∶凡脉浮大数动滑，此名阳也；沉涩弱弦微，此名阴也。阴病
见阳脉者生，阳病见阴脉者死。
寸口脉微，名曰阳不足，阴气上入阳中，则洒淅恶寒也。尺脉弱，名曰阴不足，阳气下陷入阴
中，则发热
也。阳脉浮、阴脉弱者，则血虚，血虚则筋急也。
其脉沉者，荣气之微也。其脉浮而汗出如流珠者，卫气之衰也。寸口脉浮为在表，沉为在里，
数为在腑，迟为在脏。若脉浮大者，气实血虚也。
寸口脉浮而紧，浮则为风，紧则为寒，风则伤卫，寒则伤荣，荣卫俱病，骨节烦疼，当发其
汗也。
夏月盛热，欲着复衣，冬月盛寒，欲裸其身，所以然者，阳微则恶寒，阴弱则发热。
寸口脉浮大，而医反下之，此为大逆。浮则无血，大则为寒，寒气相搏，则为肠鸣。医乃不知
而反饮冷水，令汗大出，水得寒气，冷必相搏，其人即KT 。
诸脉浮数，当发热而反洒淅恶寒，若有痛处，饮食如常者，当发其痈。脉数不时，则生恶疮也。
Chapter 4 states: There is a method of distinguishing Yin and Yang in pulse diagnosis. What does this mean? The response is: Exhalation involves the Heart and Lung, while inhalation involves the Kidney and Liver. Between breaths, the Spleen receives the essence of grains, and its pulse is located in the middle. A floating pulse indicates Yang, and a deep pulse indicates Yin; hence, they are called Yin and Yang. Both the Heart and Lung pulses present as floating; how can they be distinguished? The response is: A pulse that is floating, large, and dispersed belongs to the Heart; a pulse that is floating, short, and choppy belongs to the Lung. Both the Kidney and Liver pulses present as deep; how can they be distinguished? The response is: A pulse that is firm and long upon deep palpation belongs to the Liver; a pulse that feels soft upon deep pressure but becomes solid upon light lifting belongs to the Kidney. The Spleen resides in the central region (Zhongzhou), so its pulse is in the middle. This constitutes the method of distinguishing Yin and Yang.
Chapter 6 states: There are conditions of excess Yin with deficient Yang, and excess Yang with deficient Yin. What does this mean? The response is: If the pulse is thready and small upon superficial palpation (Fu) but solid and large upon deep palpation (Chen), it is termed excess Yin and deficient Yang. If the pulse is thready and small upon deep palpation but solid and large upon superficial palpation, it is termed excess Yang and deficient Yin. This illustrates the meaning of Yin-Yang deficiency and excess.
Chapter 9 states: How can one distinguish diseases of the Zang and Fu organs? The response is: A rapid pulse (Shu) indicates a Fu organ disease, while a slow pulse (Chi) indicates a Zang organ disease. Rapidness indicates Heat, and slowness indicates Cold. All Yang conditions tend toward Heat, and all Yin conditions tend toward Cold; thus, these characteristics allow for the differentiation of Zang and Fu diseases.
Chapter 14 states: If there is a pulse in the upper portion but none in the lower portion, the patient should vomit; if vomiting does not occur, death ensues. If there is no pulse in the upper portion but a pulse exists in the lower portion, although the condition is critical, it will not prove fatal. The reason is that the presence of the Chi pulse (at the wrist) is like the root of a tree; even if the branches and leaves wither, the root remains alive and can regenerate. Pulses have a root, and humans possess Yuan Qi (Original Qi); therefore, death is avoided.
Question: What is meant by the distinction of Yin and Yang in pulses? Answer: Pulses that are Floating (Fu), Large (Da), Rapid (Shu), Surging (Dong), or Slippery (Hua) are named Yang pulses. Pulses that are Deep (Chen), Choppy (Se), Weak (Ruo), Wiry (Xian), or Minute (Wei) are named Yin pulses. When a Yin disease presents with a Yang pulse, survival is indicated; when a Yang disease presents with a Yin pulse, death is indicated.
A faint pulse at the Cun Kou (Radial Artery) is named insufficient Yang, where Yin Qi ascends into the Yang region, causing chills and aversion to cold. A weak pulse at the Chi position is named insufficient Yin, where Yang Qi sinks into the Yin region, causing fever. If the Yang pulse is floating and the Yin pulse is weak, it indicates Blood Deficiency, which leads to tendon tension.
A deep pulse indicates slight Ying Qi (Nutritive Qi). A floating pulse accompanied by sweat droplets resembling beads indicates decline of Wei Qi (Defensive Qi). A floating pulse at Cun Kou indicates an exterior syndrome; a deep pulse indicates an interior syndrome; a rapid pulse indicates a Fu organ syndrome; a slow pulse indicates a Zang organ syndrome. If the pulse is floating and large, it indicates Qi Excess and Blood Deficiency.
A floating and wiry pulse at Cun Kou suggests that floating indicates Wind pathogen and wiry indicates Cold pathogen. Wind injures Wei Qi, and Cold injures Ying Qi. When both Ying and Wei are diseased, causing severe bone and joint pain, diaphoresis (sweating therapy) should be employed.
In midsummer intense heat, if one desires to wear heavy clothing, and in midwinter intense cold, if one desires to strip naked, it is because slight Yang causes aversion to cold, and weak Yin causes fever.
If the Cun Kou pulse is floating and large, and the physician erroneously applies purgative methods, this is a major contraindication. Floating indicates lack of Blood, and large indicates Cold. When Cold qi clashes, borborygmus (intestinal rumbling) occurs. If the physician fails to recognize this and instead forces the patient to drink cold water to induce profuse sweating, the water meets the Cold qi, and the cold clash results in dry heaves (or hiccups).
When various pulses are floating and rapid, fever is expected, yet the patient experiences chills and aversion to cold. If there is a specific painful area but appetite remains normal, an abscess (Yong) should be suspected. Irregular rapid pulses indicate the development of malignant sores.