In addition to feeling good, masturbation is a good way of relieving the sexual tension that can build up over time, especially for people without partners or whose partners are not willing or available for sex. Masturbation also is a safe sexual alternative for people who wish to avoid pregnancy and the dangers of sexually transmitted diseases. It also is necessary when a man must give a semen sample for infertility testing or for sperm donation. When sexual dysfunction is present in an adult, masturbation may be prescribed by a sex therapist to allow a person to experience an orgasm (often in women) or to delay its arrival (often in men).
