Hypogonadism describes a condition in which the sex glands do not produce a normal or sufficient amount of hormones. The condition can affect both men and women; the hormones and glands involved vary by sex. In men, the glands are the testes, or testicles, and the hormone is testosterone. In women, the glands are the ovaries, and the hormone is estrogen. Acquired hypogonadism occurs later in life due to an external cause such as an injury or infection.