Diminished hormone levels interfere with optimum sexual function by their affect on sexual desire and hormonally sensitive tissues.
Sexual desire, or libido, consists of thinking about sex, fantasizing about sex, the development of "sexual tension" and the awareness of a need for sexual release. Some people may call feeling this way as being "horny". It motivates us to initiate and participate in sex and if circumstances require, search for a sexual partner.
Lack of, or diminished sexual desire and loss of sexual motivation is sometimes referred to as a "desire phase" disorder.