The dryness of the tongue with the redness of the tongue and less moss is caused by heat injury to the yin, yin deficiency and fire (deficiency of yin essence in the body and hyperactive fire). 1. Heat injury to the yin, refers to the feeling of the four seasons of warmth and heat caused by the acute fever, manifested as strong heat, red face, sweat, thirst for cold drinks, moss yellow dry and other symptoms. Its rapid onset, the heat is heavy, so it is most likely to be dry and injure the yin, and therefore the yin to become one of the basic rules of treatment of warm diseases. 2. Yin deficiency and fire refers to the deficiency of yin and fluid, hyperactive fire, yin deficiency, hyperactivity of yang and generate heat into virtual fire, with common symptoms such as heartburn and insomnia, dry mouth and throat, night sweating (sweating abnormally after falling asleep and stopping sweating after waking up), seminal emission, short and yellow urination, dry and knotty stools, red tongue with little fluids, and thin and countless pulse (the pulse becomes narrower and finer, and the rate accelerates). Dry tongue with red tongue and little moss may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or therapy.