脉。《内经》曰∶按之不鼓，诸阳皆然，即此谓也。故凡洪大无神者，即阴虚也；细小无神者，即
阳虚也。阴虚则金水亏残，龙雷易炽，而五液神魂之病生焉。或盗汗遗精，或上下失血，或惊忡不
宁，或咳喘劳热。阳虚则火土受伤，真气日损，而君相化源之病生焉。或头目昏眩，或膈塞胀满，
或呕恶亡阳，或泻痢疼痛。救阴者，壮水之主；救阳者，益火之源。渐长则生，渐消则死，虚而不
补，元气将何以复？此实死生之关也。医不识此，尚何望其他焉？
实脉 邪气实也，举按皆强，鼓动有力。实脉有阴有阳，凡弦洪紧滑之属，皆相类也，为三焦壅
滞之候。表邪实者，浮大有力，以风寒暑湿外感于经，为伤寒瘴疟，为发热头痛、鼻塞头肿，为筋
骨肢体酸疼、痈毒等证。里邪实者，沉实有力，因饮食七情内伤于脏，为胀满，为闭结，为 瘕，
为瘀血，为痰饮，为腹痛，为喘
呕咳逆等证。火邪实者，洪滑有力，为诸实热等证。寒邪实者，沉弦有力，为诸痛滞等证。凡其在
气在血，脉有兼见者，当以类求。然实脉有真假，真实者易知，假实者易误。故必问其所因，而兼
察形证，必得其神，方是高手。
持脉之道，须明常变。凡众人之脉，有素大素小，素阴素阳者，此其赋自先天，各成一局也。
邪变之脉，有倏缓倏疾，乍进乍退者，此其病之骤至，脉随气见也。故凡诊脉者，必须先识脏脉，
而后可以察病脉；先识常脉，而后可以察变脉。于常脉中可察人之器局寿夭，于变脉中可察人之疾
病吉凶，诊家大要，当先识此。
脉象。《黄帝内经》说：按压脉搏时感觉不鼓动有力，各种阳证都是如此，指的就是这个意思。所以凡是脉象洪大但缺乏神气的，就是阴虚；凡是脉象细小但缺乏神气的，就是阳虚。阴虚则肺金和肾水亏损残败，龙雷之火（相火）容易炽盛，从而产生五液（津液）和神魂方面的疾病。或者出现盗汗、遗精，或者上下部位出血，或者惊恐心悸、心神不宁，或者咳嗽气喘、劳热。阳虚则心火和脾土受到损伤，真气日益损耗，从而产生君火和相火化源方面的疾病。或者出现头目昏眩，或者胸膈痞塞胀满，或者呕吐恶心导致亡阳，或者腹泻痢疾伴有疼痛。救治阴虚的，要壮旺真阴的根本（壮水之主）；救治阳虚的，要补益真阳的源头（益火之源）。脉气逐渐生长旺盛则生机恢复，逐渐消减则走向死亡，身体虚弱而不进行补益，元气又怎么能恢复呢？这实在是决定生死的关键所在。医生如果不认识这一点，还指望他懂得其他什么呢？
实脉 是邪气亢盛的表现，轻取重按都感觉强劲，搏动有力。实脉有阴实和阳实之分，凡是弦脉、洪脉、紧脉、滑脉等类型，都属于同类，是三焦气机壅滞的征候。表邪实的，脉象浮大而有力，是因为风寒暑湿外邪侵袭经络，表现为伤寒、瘴疟，表现为发热头痛、鼻塞头肿，表现为筋骨肢体酸痛、痈毒等症状。里邪实的，脉象沉实有力，是因为饮食不节或七情内伤脏腑，表现为胀满，表现为二便闭结，表现为癥瘕积聚，表现为瘀血，表现为痰饮，表现为腹痛，表现为气喘、呕吐、咳嗽气逆等症状。火邪实的，脉象洪滑有力，表现为各种实热等症状。寒邪实的，脉象沉弦有力，表现为各种疼痛阻滞等症状。凡是在气分或在血分，脉象有兼见的情况，应当根据类别来推求。然而实脉有真假之分，真实的实脉容易识别，虚假的实脉容易误诊。所以必须询问发病的原因，同时兼察形体症状，必须把握到脉的神气，这才是高明的医生。
诊脉的方法，必须明白常脉与变脉的区别。一般人的脉象，有的本来偏大，有的本来偏小，有的偏阴，有的偏阳，这是他们先天禀赋不同，各自形成一种格局。邪气变化引起的脉象，有的突然变缓，有的突然变快，有时进锐有时退弱，这是病邪骤然到来，脉象随着气机的变化而显现。所以凡是诊脉的人，必须先认识正常的脏脉，然后才能察知病变的脉象；先认识正常的脉象，然后才能察知变化的脉象。在正常脉象中可以观察一个人的体质格局和寿命长短，在变化脉象中可以观察一个人的疾病吉凶，这是诊脉家的主要要领，应当首先认识到这一点。
Pulse. The *Neijing* (Yellow Emperor's Inner Classic) states: "When pressed, it does not surge; this applies to all Yang conditions." This refers to the aforementioned concept. Therefore, any pulse that is surging and large but lacks *Shen* (Spirit/Vitality) indicates Yin Deficiency (Yin Xu); any pulse that is fine and small but lacks *Shen* indicates Yang Deficiency (Yang Xu). Yin Deficiency leads to the depletion of Lung Metal and Kidney Water, causing the Dragon and Thunder Fire (Ministerial Fire/Xiang Huo) to easily blaze, thereby generating diseases of the Five Fluids (Wu Ye) and the Soul/Spirit (Hun/Shen). Symptoms may include night sweats and seminal emission, bleeding from upper or lower orifices, palpitations with fright and restlessness, or coughing, wheezing, and consumptive fever. Yang Deficiency damages Heart Fire and Spleen Earth, causing the True Qi to diminish daily, thereby generating diseases of the Source of Lord Minister Fire (Jun Xiang Hua Yuan). Symptoms may include dizziness and blurred vision, chest diaphragm obstruction and distension, vomiting and nausea leading to Yang Collapse, or diarrhea and dysentery accompanied by pain. To rescue Yin, one must strengthen the master of Water (Zhuang Shui Zhi Zhu); to rescue Yang, one must benefit the source of Fire (Yi Huo Zhi Yuan). If the pulse gradually grows, life is preserved; if it gradually fades, death ensues. If deficiency is not tonified, how can the Original Qi (Yuan Qi) recover? This is truly the pass between life and death. If a physician does not understand this, what hope is there for them to understand anything else?
Excess Pulse (Shi Mai): Indicates an excess of pathogenic factors. It feels strong upon both superficial and deep pressure, with vigorous movement. Excess pulses have Yin and Yang aspects. Pulses such as String-taut (Xian), Surging (Hong), Tight (Jin), and Slippery (Hua) are similar in nature and indicate stagnation in the Triple Burner (San Jiao). For exterior excess pathogens, the pulse is floating, large, and forceful, caused by external contraction of Wind-Cold, Summer-Heat, or Dampness in the meridians, manifesting as Cold Damage (Shang Han), Miasmic Malaria, fever, headache, nasal congestion, head swelling, soreness and pain of sinews, bones, and limbs, carbuncles, and toxic sores. For interior excess pathogens, the pulse is deep, solid, and forceful, caused by internal injury to the Zang organs due to dietary irregularities or Seven Emotions, manifesting as distension and fullness, constipation and urinary retention, masses (Zheng/Jia), blood stasis, phlegm-fluid retention, abdominal pain, wheezing, vomiting, coughing, and rebellious Qi. For Fire excess pathogens, the pulse is surging, slippery, and forceful, manifesting as various excess-heat conditions. For Cold excess pathogens, the pulse is deep, string-taut, and forceful, manifesting as various painful stagnations. Whether the pathology lies in Qi or Blood, if the pulse shows combined characteristics, one should deduce based on categories. However, Excess pulses have true and false forms. True excess is easy to know; false excess is prone to misdiagnosis. Thus, one must inquire into the etiology and simultaneously observe physical signs and symptoms, grasping the *Shen* (Spirit) of the pulse, to be considered a master practitioner.
The method of taking the pulse requires understanding the Normal (Chang) and the Variable (Bian). The pulses of ordinary people may naturally be large or small, Yin-type or Yang-type; this is their innate endowment, each forming its own pattern. Pulses altered by pathogens may suddenly become slow or rapid, advancing or retreating abruptly; this indicates the sudden arrival of disease, where the pulse manifests according to Qi changes. Therefore, any practitioner diagnosing pulses must first recognize the normal Zang organ pulses before they can detect pathological pulses; they must first recognize normal pulses before they can detect variable pulses. From normal pulses, one can observe a person's constitutional structure and longevity; from variable pulses, one can observe the auspicious or ominous prognosis of illness. These are the major essentials of pulse diagnosis, which must be recognized first.