Yin deficiency internal heat is the body’s yin fluid is insufficient, can not moisten the internal organs, resulting in yang qi biased hyperactive and caused by false heat symptoms, the tongue can be seen in the tongue thin small red, tongue moss is small, tongue surface dry, and so on. Yin deficiency can not fill the tongue, tongue loss of moistening, so see the tongue thin small; yin deficiency fire (Yin essence loss in the body, there is a deficiency of fire), internal heat on the inflammation, accelerate the blood line, so see the tongue red; internal heat depletion of fluid, so the tongue is more dry tongue or even cracks on the tongue; yin deficiency, can not be on the tide in the tongue, so see the reduction of tongue moss, and even tongue moss peeling. Yin deficiency and internal heat can also be seen in dry mouth and throat, hot flashes (a burst of heat), night sweats (abnormal sweating after going to sleep, waking up after sweating stops), five heart-heat (two palms and two feet of the heart of the heat, and self-consciousness of the heart and chest heat), insomnia and other systemic symptoms. Patients with symptoms of Yin deficiency and internal heat need to consult a doctor in time. Individuals should not make diagnosis or use medication on their own to avoid adverse consequences.