《黄帝内经·灵枢·禁服》
脉陷下不起的只采用灸法。寸口脉下陷，为血凝于脉，脉中有瘀血留着，这是因为血脉中有寒邪，所以应当施用灸法。脉既不盛大也不空虚的，根据发病的经脉，采用相应治疗。
盛则泻之，虚则补之，紧则先刺而后灸之，代则取血络而后调之，陷下则徒灸之，陷下者，脉血结于中，中有着血，血寒，故宜灸之，不盛不虚，以经取之。
For the sinking pulse that barely rise, only moxibustion is used. The sinking pulse at the Cun Kou means that blood has congealed in the pulse, and there is stasis of blood in the pulse. This is because there is cold evil in the blood vessels, so moxibustion should be used. If the pulse is neither strong nor empty, treat it according to the affected meridian.