There is no such thing as which one is more serious, it is two different types of evidence, with different clinical manifestations and treatments. Yin deficiency is mostly due to the late stage of fever, or miscellaneous diseases for a long time, depletion of yin fluid, or emotional excess, fire evil injury to the yin, or room and board, depletion of yin essence, or over-served warm and dry products, the dark depletion of yin fluid, or old age and physical decline, yin fluid deficiency due to. Patients with yin deficiency are characterized by emaciation, dry mouth and throat, flushing of the cheekbones (redness of the cheekbone area on both sides of the face), heat in the heart (heat in the heart of the hands and feet, and consciously hot in the heart and chest), hot flashes (a burst of heat), night sweating (abnormal sweating after falling asleep, and sweating stops after waking up), short, yellowish urine, and dry, knotty stools, etc. The treatment is to nourish yin and clear away heat (nourish the yin essence, and clear away the heat evils). Yang deficiency is mostly caused by prolonged illness, or further development of qi deficiency, or living in a cold place for a long time, or overdosing on bitter, cold and cool products, which depletes yang qi, or the life fire of the old fading into becoming. Yang deficiency patients manifested as fear of cold, cold limbs, thirst, or like hot drinks, or self-sweating (involuntary sweating during the day, the slightest movement of sweating aggravated), urination or urinary edema, thin stools, pale, etc., the treatment of warming the yang and benefit the main qi. If there is any related condition, it is recommended to treat under the guidance of a professional physician to identify the symptoms, and not blindly self-medication.