灵枢经·血络论 Discourse on the Blood Network Vessels
黄帝曰：愿闻其奇邪而不在经者。歧伯曰：血络是也。
黄帝曰：刺血络而仆者，何也？血出而射者，何也？血少黑而浊者，何也？血出清而半为汁者，何也？拔针而肿者，何也？血出若多若少而面色苍苍者，何也？拔针而面色不变而烦悗者，何也？多出血而不动摇者，何也？愿闻其故。
歧伯曰：脉气盛而血虚者，刺之则脱气，脱气则仆。
血气俱盛而阴气多者，其血滑，刺之则射；阳气蓄积，久留而不写者，其血黑以浊，故不能射。
新饮而液渗于络，而未合和于血也，故血出而汁别焉；其不新饮者，身中有水，久则为肿。
阴气积于阳，其气因于络，故刺之血未出而气先行，故肿。
阴阳之气，其新相得而未和合，因而写之，则阴阳俱脱，表里相离，故脱色而苍苍然。
刺之血出多，色不变而烦悗者，刺络而虚经，虚经之属于阴者，阴脱，故烦悗。
阴阳相得而合为痹者，此为内溢于经，外注于络。如是者，阴阳俱有馀，虽多出血而弗能虚也。
黄帝曰：相之奈何？歧伯曰：血脉者，盛坚横以赤，上下无常处，小者如针，大者如筋，则而写之万全也，故无失数矣。失数而反，各如其度。
黄帝曰：针入而肉著者，何也？歧伯曰：热气因于针，则针热，热则内著于针，故坚焉。
Huangdi said: "I wish to hear about the strange evils that do not reside within the channels." Qibo said: "These are found in the blood network vessels."
Huangdi said: "When one needles a blood network vessel and the patient collapses, what does this mean? When the blood spurts out in a jet, what does this mean? When the blood is scant, dark, and turbid, what does this mean? When the blood that flows out is clear and half of it is like a watery fluid, what does this mean? When swelling occurs after the needle is withdrawn, what does this mean? When the blood that flows out is sometimes copious, sometimes scant, and the complexion turns pale and ashen, what does this mean? When the complexion does not change after the needle is withdrawn but the patient feels vexed and oppressed, what does this mean? When much blood is let yet the patient shows no distress at all, what does this mean? I wish to hear the reasons for these."
Qibo said: "When the vessel qi is exuberant but the blood is deficient, needling will cause the qi to collapse and be lost; when qi collapses, the patient falls."
When blood and qi are both exuberant and yin qi predominates, the blood flows smoothly, and needling causes it to spurt out. When yang qi has accumulated and stagnated for a long time without being drained, the blood is dark and turbid, and therefore cannot spurt out.
When one has just drunk fluids and they have seeped into the network vessels without yet blending with the blood, the blood that flows out will be accompanied by a separate watery fluid. In one who has not recently drunk fluids, if there is water lodged within the body, in time this will become swelling.
When yin qi has accumulated within yang and this qi has settled into the network vessels, then upon needling, before the blood emerges the qi moves out first, and so swelling results.
When the qi of yin and yang have only just come together and have not yet fully harmonized, if one then drains them, both yin and yang collapse together, exterior and interior become separated from each other, and so the complexion is drained of color and turns pale and ashen.
When needling causes much blood to flow out, yet the complexion does not change though the patient feels vexed and oppressed, this is because the network vessel has been needled while the channel itself has been left deficient; when the deficient channel belongs to yin, yin then collapses, and so the patient feels vexed and oppressed.
When yin and yang come together and combine to form impediment (bi), this is because pathogenic qi overflows the channels within and pours into the network vessels without. In such a case, both yin and yang have a surplus, and so even though much blood is let out, this cannot cause deficiency.
Huangdi said: "How does one assess this?" Qibo said: "The blood vessels to be needled are exuberant, firm, distended, and red, running crosswise without a fixed location above or below; the smaller ones are like a needle, the larger ones like a sinew. To needle and drain them according to this observation is entirely safe, and one will not fail to hit the proper measure. If one fails to observe the proper measure and acts contrary to it, the consequences will each correspond to their own degree of error."
Huangdi said: "Why does the flesh sometimes cling to the needle once it has been inserted?" Qibo said: "When heat qi gathers around the needle, the needle becomes hot; once hot, the flesh clings to the needle internally, and so it becomes firmly fixed."