Male hypogonadism refers to the failure of the male gonads, the testes, to produce enough testosterone and/or sperm.  This may be the result of defects of the testes themselves (primary hypogonadism) or of the hypothalamus or pituitary gland (secondary hypogonadism).

Erectile dysfunction, or the inability to develop or maintain an erection of the penis for satisfactory sexual intercourse, may be a symptom of male hypogonadism.