A buildup of sexual arousal and stimulation can lead men and women to the intense and pleasurable release of sexual tension known as the orgasm. Having an orgasm may also be referred to as "climaxing" or "coming." During orgasm, the heart beats faster, blood pressure rises, breath becomes quicker and heavier, and involuntary muscle contractions occur in the genitals and often throughout the body.
In men, the muscle contractions result in ejaculation or the release of sperm-filled semen from the penis. For men, therefore, orgasm is required for conception. In women, orgasm is not required for conception and orgasm does not always accompany sexual arousal.
Orgasm has many psychological effects. Most notably, orgasm is associated with the release in the brain of the neurotransmitter dopamine, which facilitates the experience of pleasure. In addition, the brain releases the hormone oxytocin, and it reinforces feelings of love and attachment. Other neurochemical changes induce alternations in pain sensation, a state of relaxation, and positive mood.
After ejaculation, men generally require a period of anywhere from a few minutes to a few hours or even days before another orgasm is possible. Women, on the other hand, can often experience simultaneous and multiple orgasms within a short period of time, if stimulating activities continue.
While it is possible to enjoy sexual activity without reaching orgasm, difficulty reaching or inability to experience orgasm can become a problem for some individuals and their sexual partners. Many such problems, and their effects on relationships, can be resolved with the help of a sexual health professional.