The tongue of kidney deficiency is divided into 2 conditions: 1) the tongue seen in kidney yang deficiency, and 2) the tongue seen in kidney yin deficiency, which are different in performance. The tongue moss seen in Kidney Yang deficiency is fat and thin and white; the tongue moss seen in Kidney Yin deficiency is usually very little moss, and the tongue is red, which is called red tongue with less moss in Chinese medicine terminology. In addition, when Kidney Yang deficiency is accompanied by cold and dampness, the tongue can be greasy. In the case of kidney yin deficiency, sometimes if the tongue is not red and less mossy, some people will have flaking moss, which is a small section of the tongue moss or a small piece of the entire tongue moss that is not present.