Lingshu · On the Blood Collaterals

The text

The Yellow Emperor said: I wish to hear of the strange pathogen that is not in the channels. Qi Bo said: It is the blood collaterals. The Yellow Emperor said: Needling the blood collaterals and falling — why? Blood coming out and shooting — why? Blood little, black and turbid — why? Blood coming out clear, half of it juice — why? Withdrawing the needle and there is swelling — why? Blood coming out, whether much or little, and the face ashen — why? Withdrawing the needle, the face-color unchanged, yet vexed and oppressed — why? Much blood coming out and they are not shaken — why? I wish to hear the reasons. Qi Bo said: When vessel-qi is abundant and blood is vacuous, needling it lets qi slip away; qi slipping away, one falls. When blood and qi are both abundant and yin-qi is much, the blood is slippery; needle it and it shoots. When yang-qi stores and gathers, staying long and not drained, the blood is black and turbid, and so cannot shoot. When one has newly drunk and the fluids seep into the collaterals, not yet joined and blended with the blood, the blood comes out and the juice is told apart. Those who have not newly drunk have water in the body; long, it becomes swelling. Yin-qi gathers in yang; its qi relies on the collaterals; thus when you needle, the blood has not yet come out and qi travels first — hence swelling. The qi of yin and yang have newly found each other and not yet joined and blended; drain them then, and yin and yang both slip away, outer and inner part — hence the color slips away and is ashen. When you needle and much blood comes out, the color unchanged, yet vexed and oppressed: you have needled the collaterals and emptied the channel; the emptied channel belongs to yin; yin slipping away, hence the vexed oppression. When yin and yang find each other and join as impediment: this is overflowing within into the channels, pouring without into the collaterals. In such a one, yin and yang both have a remainder; though much blood comes out, they cannot be made vacuous. The Yellow Emperor said: How does one look at them? Qi Bo said: The blood vessels: abundant, firm, lying across and red, above and below with no fixed place; the small like a needle, the large like a sinew — take them as a rule and drain them, and you are complete and safe. Thus do not lose the count; lose the count and it turns back, each as its measure. The Yellow Emperor said: The needle enters and the flesh clings — why? Qi Bo said: Heat-qi relies on the needle, and the needle grows hot; hot, the flesh clings to the needle — hence it is firm.

The line

The Yellow Emperor said: I wish to hear of the strange pathogen that is not in the channels.

The note

The strange pathogen is not in the channels; it is in the blood collaterals. Needle them and one may fall, or blood may come out and the illness end. A collateral is a side road. When the side road is blocked, the regular channel also grows oppressed.