Hardness, generally known as impotence, is the most common male sexual dysfunction in clinical practice. Yin or Yang deficiency may lead to impotence, and should be judged in combination with other specific clinical manifestations. The incidence of impotence varies in different age groups, and the incidence increases with increasing age. Impotence with yin deficiency evidence is mostly clinically manifested as deficiency of kidney yin and yin deficiency with fire. It may be seen as soreness and pain in the waist and knees, dizziness, often accompanied by seminal emission, premature ejaculation, irritability, insomnia, forgetfulness, often feeling a sudden sensation of heat, but the body temperature is normal, thirst, dry throat, like to drink water, the shape is usually thin, the face is often red in both cheekbones, the stool is dry, the urine is small and yellow, and the tongue is relatively red. Impotence and Yang deficiency are mostly manifested clinically as a failure of the vital gate fire. The face is pale or slightly dark, the waist and knees are sore and weak and often have a chilly feeling, and the extremities are often unheated, especially the lower extremities. There is also premature ejaculation, increased frequency of stools, more unformed and loose stools, more frequent urination, increased nocturnal urination, and a pale tongue. There is a difference between Yin deficiency and Yang deficiency in impotence, which must be correctly identified. The treatment of impotence must not be blindly aphrodisiac, but should listen to the advice of a professional doctor and be tailored to the individual.