Desire (also called sex drive or libido) is the wish to engage in sexual activity. It may be triggered by thoughts, words, sights, smell, or touch. Desire leads to the first stage of the sexual response cycle, excitement. Excitement is sexual arousal. During excitement, blood flow to the penis increases, leading to an erection. Also, muscle tension increases throughout the body. In the plateau stage, excitement and muscle tension are maintained or intensified. Orgasm is the peak or climax of sexual excitement. At orgasm, muscle tension throughout the body further increases. The man experiences contractions of the pelvic muscles followed by a release of muscle tension. Semen is usually, but not always, ejaculated from the penis.
Although ejaculation and orgasm often occur nearly simultaneously, they are separate events. Ejaculation can occur without orgasm. Also, orgasm can occur in the absence of ejaculation, especially before puberty, or with the use of certain drugs (such as some antidepressants). Most men find orgasm highly pleasurable. In resolution, a man returns to an unaroused state. After orgasm, men cannot have another erection for some time (refractory period), often as short as 20 minutes or less in young men but much longer in older men. The time between erections generally increases as men age.Decreased LibidoSex drive (libido) varies greatly among men. Different men find different degrees of libido satisfactory. Libido may be decreased temporarily by conditions such as fatigue or anxiety. Libido also tends to gradually decrease as a man ages. Persistent low libido may cause a man and his sex partner distress.Occasionally, libido can be low throughout a man’s life. Lifelong low libido can result from traumatic childhood sexual experiences or from suppression of sexual thoughts. Most often, however, low libido develops after years of normal sexual desire. Psycho logic factors, such as depression, anxiety, and relationship problems, are often the cause. Some drugs (such as those used to treat high blood pressure, depression, or anxiety) and decreased levels of testosterone can also lower libido.A man with decreased libido thinks less about sex. He loses interest in sexual fantasy and masturbation, and also in sexual activity. Even sexual stimulation, by sights, words, or touch, may fail to provoke interest. The man often retains the capacity for sexual function. Some men continue to engage in sexual activity to satisfy their partner.
