Generally speaking, a white tongue is a sign of kidney yang deficiency, and kidney yin deficiency is manifested by a red tongue with little or no moss.
Kidney yang deficiency refers to the deficiency of kidney yang, the body loses its warmth, there will be a white or sallow face, fatigue (mental fatigue, physical weakness), lumbar and knee pain, nocturnal urination, pale tongue, moss white, thin and feeble pulse and other manifestations, so the kidney yang deficiency will lead to the white tongue.
Kidney yin deficiency refers to deficiency of kidney yin, loss of nourishment, internal disturbance of heat, there will be dizziness, tinnitus, hot flashes and night sweating (abnormal sweating after going to sleep, and waking up sweating stops), five heart heat (two palms and two feet of the heart fever, and consciously feel the heart and chest heat), dry throat, tongue red with little moss or moss, pulse (pulse becomes narrow and thin, and the rate of speeding up) and other manifestations, therefore, kidney yin deficiency will not cause the tongue to turn white.
However, it should be noted that white tongue is not always caused by kidney yang deficiency, but may also be caused by spleen qi deficiency, stomach qi deficiency, etc. It is recommended to consult a doctor in time for diagnosis and treatment of white tongue, and it is not recommended to make judgment on your own.