Red tongue with yellow coating may be kidney yin deficiency, usually not yang deficiency. 1. Kidney yin deficiency: patients with red tongue and yellow moss, if accompanied by internal heat and night sweating (sweating abnormally after going to sleep, waking up sweating stops), dizziness, tinnitus, waist and knee soreness and weakness (waist and knee soreness and weakness of the sensation), pulse (pulse narrowing and thinning and accelerated rate), the tongue is red, dry mouth and tongue is a manifestation of kidney yin deficiency, yin deficiency is born of heat, there may be a red tongue and yellow moss situation. 2. Yang deficiency: Yang deficiency patients manifested as fear of cold, cold hands and feet, if the kidney Yang deficiency patients manifested as loss of libido, lumbago, frequent urination, poor resistance to cold, etc. These manifestations, usually Yang deficiency manifested as the tongue pale moss white. Tongue red moss yellow there may be other reasons, it is recommended to timely hospital consultation, by the Chinese medicine practitioner to identify and treat, do not self-medication, to avoid bringing adverse consequences to the body.