Impotence, in western medicine, can occur in male sexual disorder or some chronic diseases.

(1) The disease is characterized by inability to have an erection of penis during sexual intercourse in males befare climacteric.

(2) It can be attributive to excessive sexual activities, prolonged illness, weak constitution, frequent masturbation in youngsters, accompanied by lassitude, weak loins and knees, aversion to cold, cold limbs, or difficulty in urination with dribbling urine.

(3) Impotence due to hypoplasia of sex organ or the use of drugs should be excluded.

(4) Distinguish impotence from premature ejaculation. Premature ejaculation refers to early ejaculation of semen at the beginning of sexual intercourse and inability to carry on sexual intercourse because of flaccidity of the penis immediately after the ejaculation. However, impotence means the inability to achieve a satisfactory penile erection. They present marked differences. Nonetheless, if premature ejaculation persists, impotance may ensue.