Hypogonadism is the condition in which the production of sex hormones and germ cells are inadequate. It is more prevalent in males than in females.

The gonads are the organs of sexual differentiation—in the female, they are ovaries; in the male, the testes. Along with producing eggs and sperm, they produce sex hormones that generate all the differences between men and women. If they produce too little sex hormone, then either the growth or the function of the sexual organs is impaired.

The gonads are not independent in their function, however. They are loosely controlled by the pituitary gland. The pituitary hormones are the same for males and females, but the gonadal hormones are different. Men produce mostly androgens, and women produce mostly estrogens. These two kinds of hormones regulate the development of the embryo and direct the adolescent maturation of sex organs into their adult...