Why the San Jiao has no organ sān jiāo · 三焦为何无实体

The San Jiao is the only Fu with no anatomical counterpart at all. Classical texts describe it as dividing the torso into upper, middle and lower regions for reasoning about the movement of Qi and fluids.

Its lack of physical basis is not hidden by the tradition — it is a well-known topic in TCM theory. It is a useful example of how the system is willing to include openly abstract categories.