《黄帝内经·素问·厥论》
岐伯答道：阴经之气起于足五趾的内侧端，汇集于膝下后，上聚于膝部。所以若阳经之气衰竭于下而阴经之气偏胜，就会导致从足五趾至膝部的厥冷，这种厥冷，不是由于外寒的侵入，而是由于体内的阳虚所致。
岐伯曰：阴气起于五趾之里，集于膝下而聚于膝上，故阴气胜则从五趾至膝上寒，其寒也，不从外，皆从内也。
Qibo replied: The qi of the yin meridian originates from the inner side of the five toes of the foot, gathers under the knee, and then gathers at the knee. Therefore, if the qi of the yang meridian fails at the bottom and the qi of the yin meridian is partial Sheng, it will lead to Jue cold from the five toes to the knees. This Jue cold is not caused by the invasion of external cold, but by the deficiency of yang in the body.