难经曰经脉有是动有所生病一脉辄变为二病者何也然经言是动者气也所生病者血也邪在
气气
为是动邪在血血为所生病气主 之血主濡之气留而不行者为气先病也血滞而不濡者为血后病
也故先为是动后为所生病也
经脉为里支而横者为络络之别者为孙络盛而血者疾诛之盛者泻之虚者饮药以补之(灵枢)
○经
径也径直者为经经之支派旁出者为络(入门)○络穴俱在两经中间乃交经过络之处也(入门)○
刺脏腑经络四病皆不同十五络病至浅在表也十二经病次之六腑病又次之五脏病至深在里也故
治法有难易焉至于络又各不同十五络之络乃阴经别走阳经阳经别走阴经而横贯两经之间者所
为支而横者为络是也缪刺之络乃病邪流溢大络不得入贯经 而其痛与经脉缪处乃络病经不病
者也血络之络乃皮肤所见或赤或青或黑
之络而小者如针大者如筋也以浅深言之血络至浅缪刺者次之十五络近里而贯经 也(纲目)
夫人之常数太阳常多血少气少阳常多气少血阳明常多血多气厥阴常多血少气少阴常多气
少血
太阳常多气少血此天之常数也○故曰刺阳明出血气刺太阳出血恶气刺少阳出气恶血刺太阴出
气恶血刺厥阴出血恶气刺少阴出气恶血也(灵枢)○是阳明太阴为表里足少阴厥阴为表里足太
阳少阴为表里手阳明太阴为表里手少阳心主为表里手太阳少阴为表里也(灵枢)
《难经》说：经脉有“是动”病和“所生病”，一脉却变成两种病，这是为什么呢？回答说：经文所说的“是动”，是指气方面的病变；“所生病”，是指血方面的病变。邪气在气分，气机紊乱导致“是动”病；邪气在血分，血液凝滞导致“所生病”。气主司推动（温煦、推动脏腑经络功能），血主司濡养（滋润濡养脏腑组织）。气停留而运行不畅的，是气先发生病变；血液停滞而不能濡养的，是血后发生病变。所以先出现“是动”病，后出现“所生病”。
经脉位于深层，分支横向走行的称为络脉，络脉再细分的小支称为孙络。如果络脉充盈且血液瘀盛，应当迅速刺破放血以祛除瘀血。实证用泻法，虚证用药饮来补益。（出自《灵枢》）○ 经，就是径路，直行者为经；从经分出旁侧走出的分支为络。（出自《医学入门》）○ 络穴都位于两条经脉之间，是经脉交接经过络脉的地方。（出自《医学入门》）○ 针刺治疗脏腑经络四种疾病的方法各不相同。十五络脉的病位最浅，在体表；十二经脉的病位次之；六腑的病位又次之；五脏的病位最深，在体内。所以治疗方法有难易之分。至于络脉，各自又有不同。十五络脉的络，是阴经别行走向阳经，或阳经别行走向阴经，横向贯穿两条经脉之间的部分，这就是所谓“分支横向走行的是络脉”。缪刺法所针对的络脉，是病邪流溢到大络，不能进入并贯通经脉，其疼痛部位与经脉交错错位，这是络脉有病而经脉无病的情况。血络的络，是指皮肤表面可见的，颜色或红、或青、或黑的络脉，小的如针尖粗细，大的如筋脉粗细。从深浅程度来说，血络最浅，缪刺法所用的络脉次之，十五络脉靠近体内并贯通经脉。（出自《针灸大成·纲目》）
人的气血常数规律是：太阳经通常多血少气，少阳经通常多气少血，阳明经通常多血多气，厥阴经通常多血少气，少阴经通常多气少血，太阳经通常多气少血。这是天定的常数规律。○ 所以说：针刺阳明经，可以出血和气；针刺太阳经，可以出血，避免耗气；针刺少阳经，可以出气，避免耗血；针刺太阴经，可以出气，避免耗血；针刺厥阴经，可以出血，避免耗气；针刺少阴经，可以出气，避免耗血。（出自《灵枢》）○ 因此，阳明经与太阴经互为表里，足少阴经与足厥阴经互为表里，足太阳经与足少阴经互为表里，手阳明经与手太阴经互为表里，手少阳经与心包经互为表里，手太阳经与手少阴经互为表里。（出自《灵枢》）
The *Nan Jing* (Classic of Difficult Issues) states: The meridians have "Shi Dong" diseases and "Suo Sheng" diseases. Why does one meridian manifest as two types of diseases? The answer is: The text refers to "Shi Dong" as disorders of Qi, and "Suo Sheng" as disorders of Blood. When pathogenic factors are in the Qi level, Qi dysfunction leads to "Shi Dong"; when pathogenic factors are in the Blood level, Blood stasis leads to "Suo Sheng". Qi primarily governs propulsion (warming and driving the functions of Zang-Fu organs and meridians), while Blood primarily governs nourishment (moistening and nurturing tissues). When Qi stagnates and fails to circulate smoothly, it is a prior disorder of Qi; when Blood stagnates and fails to moisten, it is a subsequent disorder of Blood. Therefore, "Shi Dong" diseases appear first, followed by "Suo Sheng" diseases.
Meridians run deep within; branches that run horizontally are called Collaterals (Luo Mai); further subdivisions of collaterals are called Sun Collaterals (Sun Luo). If collaterals are full and blood is stagnant and excessive, they should be pricked rapidly to drain the blood. Excess conditions are treated with draining methods, while deficiency conditions are treated with herbal decoctions to tonify. (From *Ling Shu*) ○ Meridian (Jing) implies a direct path; straight-running channels are Meridians; branches diverging laterally from meridians are Collaterals. (From *Yi Xue Ru Men*) ○ Luo points are located between two meridians, which are the sites where meridians intersect and pass through collaterals. (From *Yi Xue Ru Men*) ○ Acupuncture treatment for diseases of Zang-Fu organs and meridians varies according to four categories. Diseases of the fifteen Luo vessels are the most superficial, located at the surface; diseases of the twelve regular meridians are next; diseases of the six Fu organs are next; diseases of the five Zang organs are the deepest, located internally. Thus, treatment methods vary in difficulty. Regarding collaterals, each type differs. The collaterals of the fifteen Luo vessels refer to Yin meridians connecting to Yang meridians, or Yang meridians connecting to Yin meridians, running transversely between two meridians—this is what is meant by "branches running horizontally are collaterals." The collaterals targeted by Miao Needling (Mu Ci) involve pathogenic factors overflowing into large collaterals, unable to enter and penetrate the main meridians; their pain locations are displaced relative to the meridians, indicating disease in the collateral but not in the meridian itself. Blood collaterals refer to visible vessels on the skin, appearing red, blue, or black; small ones are needle-sized, large ones are tendon-sized. In terms of depth, blood collaterals are the most superficial, Miao needling collaterals are next, and the fifteen Luo vessels are closer to the interior and penetrate the meridians. (From *Zhen Jiu Da Cheng · Gang Mu*)
The constant physiological norms of human beings are: Taiyang typically has abundant blood and scarce Qi; Shaoyang typically has abundant Qi and scarce blood; Yangming typically has abundant blood and abundant Qi; Jueyin typically has abundant blood and scarce Qi; Shaoyin typically has abundant Qi and scarce blood; Taiyang typically has abundant Qi and scarce blood. These are the natural constants determined by Heaven. ○ Therefore, it is said: Needling Yangming can release both blood and Qi; needling Taiyang can release blood but should avoid depleting Qi; needling Shaoyang can release Qi but should avoid depleting blood; needling Taiyin can release Qi but should avoid depleting blood; needling Jueyin can release blood but should avoid depleting Qi; needling Shaoyin can release Qi but should avoid depleting blood. (From *Ling Shu*) ○ Thus, Yangming and Taiyin form an exterior-interior relationship; Foot Shaoyin and Foot Jueyin form an exterior-interior relationship; Foot Taiyang and Foot Shaoyin form an exterior-interior relationship; Hand Yangming and Hand Taiyin form an exterior-interior relationship; Hand Shaoyang and Pericardium (Xin Bao) form an exterior-interior relationship; Hand Taiyang and Hand Shaoyin form an exterior-interior relationship. (From *Ling Shu*)