Kidney Yin Deficiency Empty Heat. Internal cold has injured yang. In addition it may also indicate yin deficiency of the kidneys liver or heart.
A tongue without coating indicates yin deficiency first and foremost of the stomach. Yin is the root that should aanchor qi. In heart and kidney yin deficiency with empty heat however the heart downward pushing and kidney pulling is severely reduced.
In yin deficiency the tongue lacks a coating.
Yin deficiency often causes empty fire. Causes of empty heat and cold. Empty because it occurs when there is not enough cooling yin energy to combat it. When the root is weakened qi rises.