STICKY AND SLIPPERY TONGUE COATING
STICKY AND SLIPPERY TONGUE COATING There are two types of greasy coating: one is called ni 膩which I call "sticky"; the other is hua 滑 which I call "slippery". The sticky coating is more common than the slippery coating. Both types of coating share a common quality of being greasy. The main difference is that with the sticky coating the individual papillae can be seen, while the slippery coating is more greasy and oily so that individual papillae cannot be seen. Also, the sticky coating is greasy but it adheres firmly to the tongue body; the slippery coating is more oily and seems to "slip" on the surface of the tongue. Another difference is that the sticky coating may be dry (an apparent contradiction but frequent) indicating Phlegm with Dryness of Phlegm-Heat. The slippery coating cannot be dry. A possible way of visualizing the difference between these two is to imagine spreading a layer of butter on a toothbrush: if we spread it thickly and do not push...