凡用针者。必通十二经脉之所终始。营卫偕行二十八脉。此其常例。外邪病患。奇
邪离经。阴经典阳经各别。则各有根结。各有终始。阴经阳经不同。手经足经各异。用
针者应重足不重手。盖阴者主脏。阳者主腑。足三阴三阳。接近于脏腑。手三阴三阳之
脉度。不接近于脏腑。但补泻迎随。和气之方。必通阴阳脏腑。故根结偏重在足。然脉
会大渊。阴阳之有余或不足。又当从手诊脉。盖人迎主三阳。脉口主三阴。人迎一盛一
盛三盛。病在少阳太阳阳明。脉口一盛二盛三盛。病在厥阴少阴太阴。
人迎脉口。较平人俱盛三倍以上。名曰阴阳俱溢（一）。当以开十宣之法疾泻之。
不开则血脉闭塞。气无所行。流淫而伤五脏。危证也。
如四倍以上。左为外格（一）。右为内关（一）。内关不通。死不治。
人迎脉口。较平人俱盛四倍以上者。名曰关格。与之短期。盖阴阳离绝。生气已竭
之死证也。
其人迎一盛于脉口者。病在足少阳。一盛而躁者。病在手少阳。用针者。皆泻足少
阳而补足厥阴。二泻一补。日一取之。
其人迎二盛于脉口者。病在足太阳。二盛而躁者。病在手太阳。用针者。皆泻足太
阳而补足少阴。二泻一补。二日一取之。
其人迎三盛于脉口者。病在足阳明。三盛而躁者。病在手阳明。用针者。皆泻足阳
明。而补足太阴。二泻一补。日二取之。
其脉口一盛于人迎者。病在足厥阴。一盛而躁者。病在手厥阴。用针者。皆泻足厥
阴而补足少阳。二补一泻。日一取之。
其脉口二盛于人迎者。病在足少阴。二盛而躁者。病在手少阴。用针者。皆泻足少
阴而补足太阳。二补一泻。二日一取之。
其脉口三盛于人迎者。病在足太阴。三盛而躁者。病在手太阴。用针者。皆泻足太
阴。而补足阳明。二补一泻。日二取之。
刺道毕于终始。终始之道。有常有变。经脉十二。始于手太阴肺。终于足厥阴肝。
脉度二十有八。男子始于左手太阴肺。终于督任两阳跷。女子始于右手太阴肺。终于
任督两阴跷。此经脉终始之常。外有经正经别六合。不在其中。皆人身生理之常。其有
病变者。则三阴三阳各有终始。各有根结。推而言之。尤有根而不结者。散于络别而倒
行。会于项中。始于任而终于督。七次八穴十四行（二）。尚未尽也。此根而不结之变例。
（一）太阳根于至阴。结于命门。（睛明穴）
（二）阳明根于厉兑。结于颡大。（头维穴）
（三）少阳根于窍阴。结于窗笼。（听宫穴）
（四）太阴根于隐白。结于太仓。（中腕穴）
（五）少阴根于涌泉。结于廉泉。（舌本穴）
（六）厥阴根于大敦。结于玉英。（玉堂穴）
以上六者。有根有结。重足不重手。盖足三阴三阳之井穴。皆在足下。故也。
（一）足太阳根于至阴。溜于京骨。注于昆仑。入于天柱。六次脉飞阳也。
（二）足少阳根于窍阴。溜于丘虚。注于阳辅。入于天容。四次脉光明也。
（三）足阳明根于厉兑。溜于冲阳。注于下陵。入于人迎。一次脉丰隆也。
（四）手太阳根于少泽。溜于阳谷。注于小海。入于天窗。三次脉支正也。
（五）手少阳根于关冲。溜于阳池。注于支沟。入于天牖。五次脉外关也。
（六）手阳明根于商阳。溜于合谷。注于阳溪。入于扶突。二次脉偏历也。
以上六者。手足三阳之别络也。根而无结。重阳不重阴。盖手之三阴。从胸走手。
不上于头。故不计也。
凡是用针治病的人，必须通晓十二经脉的起止走向。营气和卫气共同运行于二十八脉之中，这是正常的规律。如果是外邪致病，病邪偏离了常规经络，阴经和阳经各自有别，那么它们就各有其“根”与“结”，也各有其起始和终止之处。阴经与阳经不同，手经与足经也各异。使用针刺疗法时，应当重视足部穴位而不轻视手部穴位。这是因为阴经主要联系五脏，阳经主要联系六腑。足部的三阴经和三阳经距离脏腑较近，而手部的三阴经和三阳经的脉度（路径）距离脏腑较远。虽然补法和泻法、迎随补泻以及调和气血的方法，都必须通晓阴阳和脏腑的关系，但“根结”理论更侧重于足部。然而，脉诊汇聚于太渊穴，判断阴阳的有余或不足，又应当从手部诊察脉搏。因为人迎脉主要反映三阳经的情况，寸口脉（脉口）主要反映三阴经的情况。人迎脉比平人脉象盛大一倍、两倍、三倍时，病分别在少阳、太阳、阳明经；寸口脉比平人脉象盛大一倍、两倍、三倍时，病分别在厥阴、少阴、太阴经。
如果人迎脉和寸口脉都比正常人的脉象盛大三倍以上，这叫做“阴阳俱溢”。应当立即采用刺十宣穴放血的方法来急泻邪气。如果不进行泻法，就会导致血脉闭塞，气机无法运行，进而流散淫溢并损伤五脏，这是危重的证候。
如果盛大四倍以上，左侧为“外格”，右侧为“内关”。内关不通，则死亡且无法治疗。
如果人迎脉和寸口脉都比正常人的脉象盛大四倍以上，这叫做“关格”。此时应告知家属病人已不久于人世。这是因为阴阳离绝，生气已经竭尽的死证。
如果人迎脉比寸口脉盛大一倍，病在足少阳经；如果盛大一倍且脉象躁动，病在手少阳经。用针者，都应泻足少阳经，补足厥阴经，采取二泻一补的方法，每天取穴一次。
如果人迎脉比寸口脉盛大两倍，病在足太阳经；如果盛大两倍且脉象躁动，病在手太阳经。用针者，都应泻足太阳经，补足少阴经，采取二泻一补的方法，每两天取穴一次。
如果人迎脉比寸口脉盛大三倍，病在足阳明经；如果盛大三倍且脉象躁动，病在手阳明经。用针者，都应泻足阳明经，补足太阴经，采取二泻一补的方法，每天取穴两次。
如果寸口脉比人迎脉盛大一倍，病在足厥阴经；如果盛大一倍且脉象躁动，病在手厥阴经。用针者，都应泻足厥阴经，补足少阳经，采取二补一泻的方法，每天取穴一次。
如果寸口脉比人迎脉盛大两倍，病在足少阴经；如果盛大两倍且脉象躁动，病在手少阴经。用针者，都应泻足少阴经，补足太阳经，采取二补一泻的方法，每两天取穴一次。
如果寸口脉比人迎脉盛大三倍，病在足太阴经；如果盛大三倍且脉象躁动，病在手太阴经。用针者，都应泻足太阴经，补足阳明经，采取二补一泻的方法，每天取穴两次。
针刺的道理终结于“终始”篇。终始之道，有常理也有变通。十二经脉，始于手太阴肺经，终于足厥阴肝经。二十八脉的长度，男子始于左手太阴肺经，终于督脉和任脉及两条阳跷脉；女子始于右手太阴肺经，终于任脉、督脉及两条阴跷脉。这是经脉终始的常理。此外还有经别、正经别络六合等，不在上述二十八脉之列，这些都是人身生理的常态。如果有病变发生，那么三阴三阳各有其终始，各有其根结。推而言之，还有只有根而没有结的情况，它们散布于络脉和别络中倒行，汇聚于项部，始于任脉而终于督脉，共有七次、八穴、十四行，尚未尽述。这是“有根无结”的变例。
（一）足太阳膀胱经根于至阴穴，结于命门（睛明穴）。
（二）足阳明胃经根于厉兑穴，结于颡大（头维穴）。
（三）足少阳胆经根于窍阴穴，结于窗笼（听宫穴）。
（四）足太阴脾经根于隐白穴，结于太仓（中脘穴）。
（五）足少阴肾经根于涌泉穴，结于廉泉（舌本穴）。
（六）足厥阴肝经根于大敦穴，结于玉英（玉堂穴）。
以上六种情况，既有根又有结，强调足部而不强调手部。这是因为足三阴三阳的井穴都在足下，所以如此。
（一）足太阳膀胱经根于至阴穴，流经京骨穴，注入昆仑穴，进入天柱穴，共六次，脉气飞阳。
（二）足少阳胆经根于窍阴穴，流经丘墟穴，注入阳辅穴，进入天容穴，共四次，脉气光明。
（三）足阳明胃经根于厉兑穴，流经冲阳穴，注入下陵穴，进入人迎穴，共一次，脉气丰隆。
（四）手太阳小肠经根于少泽穴，流经阳谷穴，注入小海穴，进入天窗穴，共三次，脉气支正。
（五）手少阳三焦经根于关冲穴，流经阳池穴，注入支沟穴，进入天牖穴，共五次，脉气外关。
（六）手阳明大肠经根于商阳穴，流经合谷穴，注入阳溪穴，进入扶突穴，共二次，脉气偏历。
以上六种情况，是手足三阳经的别络。只有根而没有结，强调重阳经而不重阴经。这是因为手部的三阴经，从胸部走向手部，不向上到达头部，所以不计入此类。
Any practitioner using acupuncture must understand the starting and ending points of the twelve primary meridians. Ying (Nutrient) Qi and Wei (Defensive) Qi circulate together through twenty-eight vessels; this is the normal pattern. In cases of exogenous pathogenic factors, when pathogens deviate from the regular meridians, Yin meridians and Yang meridians are distinct, each having its own "Root" (Gen) and "Knot" (Jie), as well as specific starting and ending points. Yin meridians differ from Yang meridians, and Hand meridians differ from Foot meridians. Acupuncturists should prioritize Foot points over Hand points. This is because Yin meridians primarily govern the Zang organs, while Yang meridians primarily govern the Fu organs. The three Yin and three Yang meridians of the feet are closer to the Zang and Fu organs, whereas the pathways of the three Yin and three Yang meridians of the hands are relatively distant from the organs. Although tonification and sedation techniques, such as following and opposing methods, and strategies for harmonizing Qi require a thorough understanding of Yin-Yang and organ relationships, the theory of Roots and Knots places greater emphasis on the feet. However, pulse diagnosis converges at Taiyuan (LU-9); to assess excess or deficiency of Yin and Yang, one should palpate the pulses at the hands. Specifically, the Renying (Carotid) pulse reflects the state of the three Yang meridians, while the Maikou (Cun Kou/Wrist) pulse reflects the state of the three Yin meridains. If the Renying pulse is one-fold, two-fold, or three-fold stronger than the normal pulse, the disease resides in the Shaoyang, Taiyang, or Yangming meridians, respectively. If the Maikou pulse is one-fold, two-fold, or three-fold stronger than the normal pulse, the disease resides in the Jueyin, Shaoyin, or Taiyin meridians, respectively.
If both the Renying and Maikou pulses are more than three times stronger than those of a healthy person, it is termed "Yin and Yang Overflow" (Yin Yang Ju Yi). One should immediately employ rapid sedation by pricking the Ten Xuan points. If not treated with sedation, blood vessels will become blocked, Qi will fail to circulate, leading to pathological dispersion that damages the five Zang organs, resulting in a critical condition.
If the pulses are four times stronger than normal, left-sided excess indicates "Outer Gridlock" (Wai Ge), and right-sided excess indicates "Inner Closure" (Nei Guan). If Nei Guan occurs, death is inevitable and untreatable.
If both Renying and Maikou pulses are more than four times stronger than normal, it is termed "Gridlock and Closure" (Guan Ge). A short life expectancy should be predicted, as this signifies the separation of Yin and Yang and the exhaustion of vital Qi, which is a fatal condition.
If the Renying pulse is one-fold stronger than the Maikou pulse, the disease is in the Foot Shaoyang meridian; if it is one-fold stronger and restless, the disease is in the Hand Shaoyang meridian. The acupuncturist should sedate the Foot Shaoyang meridian and tonify the Jueyin meridian, applying two sedations and one tonification, treating once daily.
If the Renying pulse is two-fold stronger than the Maikou pulse, the disease is in the Foot Taiyang meridian; if it is two-fold stronger and restless, the disease is in the Hand Taiyang meridian. The acupuncturist should sedate the Foot Taiyang meridian and tonify the Shaoyin meridian, applying two sedations and one tonification, treating every two days.
If the Renying pulse is three-fold stronger than the Maikou pulse, the disease is in the Foot Yangming meridian; if it is three-fold stronger and restless, the disease is in the Hand Yangming meridian. The acupuncturist should sedate the Foot Yangming meridian and tonify the Taiyin meridian, applying two sedations and one tonification, treating twice daily.
If the Maikou pulse is one-fold stronger than the Renying pulse, the disease is in the Foot Jueyin meridian; if it is one-fold stronger and restless, the disease is in the Hand Jueyin meridian. The acupuncturist should sedate the Foot Jueyin meridian and tonify the Shaoyang meridian, applying two tonifications and one sedation, treating once daily.
If the Maikou pulse is two-fold stronger than the Renying pulse, the disease is in the Foot Shaoyin meridian; if it is two-fold stronger and restless, the disease is in the Hand Shaoyin meridian. The acupuncturist should sedate the Foot Shaoyin meridian and tonify the Taiyang meridian, applying two tonifications and one sedation, treating every two days.
If the Maikou pulse is three-fold stronger than the Renying pulse, the disease is in the Foot Taiyin meridian; if it is three-fold stronger and restless, the disease is in the Hand Taiyin meridian. The acupuncturist should sedate the Foot Taiyin meridian and tonify the Yangming meridian, applying two tonifications and one sedation, treating twice daily.
The principles of needling conclude with the chapter on "Endings and Beginnings." The way of endings and beginnings has both constant rules and variations. The twelve primary meridians begin at the Hand Taiyin Lung meridian and end at the Foot Jueyin Liver meridian. The twenty-eight vessel pathways: for men, they begin at the Left Hand Taiyin Lung meridian and end at the Du Mai (Governor Vessel), Ren Mai (Conception Vessel), and the two Yang Qiao vessels; for women, they begin at the Right Hand Taiyin Lung meridian and end at the Ren Mai, Du Mai, and the two Yin Qiao vessels. These are the constant patterns of meridian endings and beginnings. Additionally, there are divergent meridians and collateral connections forming six pairs, which are not included in the above twenty-eight vessels; these represent the normal physiology of the human body. In cases of pathology, however, the three Yin and three Yang meridians have their own specific endings and beginnings, roots and knots. Extending this logic, there are cases where there is a root but no knot, where Qi scatters into collaterals and divergent branches, moving inversely, converging at the nape, beginning at the Ren Mai and ending at the Du Mai. There are seven instances, eight acupoints, and fourteen pathways described, yet this does not exhaust all possibilities. These are variable examples of "having roots but no knots."
(1) Foot Taiyang Bladder meridian roots at Zhiyin (BL-67) and knots at Mingmen (Jingming, BL-1).
(2) Foot Yangming Stomach meridian roots at Lidui (ST-45) and knots at Sangda (Touwei, ST-8).
(3) Foot Shaoyall Gallbladder meridian roots at Qiaoyin (GB-44) and knots at Chuanglong (Tinggong, SI-19).
(4) Foot Taiyin Spleen meridian roots at Yinbai (SP-1) and knots at Taicang (Zhongwan, CV-12).
(5) Foot Shaoyin Kidney meridian roots at Yongquan (KI-1) and knots at Lianquan (Shaben point).
(6) Foot Jueyin Liver meridian roots at Dacun (LR-1) and knots at Yuying (Yutang, CV-19).
In the above six cases, there are both roots and knots, emphasizing the feet over the hands. This is because the Jing-Well points of the three Yin and three Yang meridians of the feet are all located on the feet.
(1) Foot Taiyang Bladder meridian roots at Zhiyin (BL-67), flows through Jinggu (BL-64), pours into Kunlun (BL-60), and enters Tianzhu (BL-10). Six times, the Feiyang (BL-58) pulse.
(2) Foot Shaoyang Gallbladder meridian roots at Qiaoyin (GB-44), flows through Qiuxu (GB-40), pours into Yangfu (GB-38), and enters Tianrong (SI-17). Four times, the Guangming (GB-37) pulse.
(3) Foot Yangming Stomach meridian roots at Lidui (ST-45), flows through Chongyang (ST-42), pours into Xialing (Zusanli, ST-36), and enters Renying (ST-9). Once, the Fenglong (ST-40) pulse.
(4) Hand Taiyang Small Intestine meridian roots at Shaoze (SI-1), flows through Yanggu (SI-2), pours into Xiaohai (SI-8), and enters Tianchuang (SI-16). Three times, the Zhizheng (SI-7) pulse.
(5) Hand Shaoyang Sanjiao meridian roots at Guanchong (SJ-1), flows through Yangchi (SJ-4), pours into Zhigou (SJ-6), and enters Tianyou (SJ-16). Five times, the Waiguan (SJ-5) pulse.
(6) Hand Yangming Large Intestine meridian roots at Shangyang (LI-1), flows through Hegu (LI-4), pours into Yangxi (LI-5), and enters Futu (LI-18). Twice, the Pianli (LI-6) pulse.
The above six cases refer to the divergent collaterals of the Hand and Foot Yang meridians. They have roots but no knots, emphasizing Yang over Yin. This is because the three Yin meridians of the hand travel from the chest to the hands and do not ascend to the head, so they are not counted in this context.