Yin and yang deficiency can be identified from the four aspects of cold and heat, tongue and pulse, mental state, accompanied by symptoms, each person’s condition is different, there is no simplest way to identify. 1. Cold and heat: Yang deficiency, generally afraid of cold, cold hands and feet, plus clothing can be relieved; yin deficiency, more often manifested as fear of heat, five heart heat (two hearts and two feet heart fever, and self-consciousness of the heart and chest heat), and so on. 2. Tongue and pulse: in Yang deficiency, the tongue is usually fat, pale and white, with a fine pulse; in Yin deficiency, the tongue is usually red with little moss, and the pulse is fine (the pulse becomes narrower and finer, and the rate is accelerated). 3. Mental state: Yang deficiency, usually indifferent, depressed, short of breath and lazy speech; Yin deficiency, usually irritable, impatient and easy to anger. 4. Accompanying symptoms: Yang deficiency may also be accompanied by lumbar and knee coldness, impotence, frequent nocturia, palpitations (rapid heartbeat, often accompanied by panic), poor appetite and other symptoms; Yin deficiency, deafness, tinnitus, dizziness, insomnia, dreamy, dry mouth and other symptoms. If symptoms of yin or yang deficiency occur, it is recommended to go to the hospital in time to avoid delaying the condition.