The orgasm is widely regarded as the peak of sexual excitement. It is a powerful feeling of physical pleasure and sensation, which includes a discharge of accumulated erotic tension. Orgasms can be defined in different ways using different criteria. Medical professionals have used physiological changes to the body as a basis for a definition, whereas psychologists and mental health professionals have used emotional and cognitive changes. A single, overarching explanation of the orgasm does not currently exist.
The female orgasm
The following description of the physiological process of female orgasm in the genitals will use the Masters and Johnson four-phase model.
When a woman is stimulated physically or psychologically, the blood vessels within her genitals dilate. Increased blood supply causes the vulva to swell, and fluid to pass through the vaginal walls, making the vulva swollen and wet. Internally, the top of the vagina expands.
Heart rate and breathing quicken and blood pressure increases. Blood vessel dilation can lead to the woman appearing flushed, particularly on the neck and chest.
As blood flow to the introitus – the lower area of the vagina – reaches its limit, it becomes firm. Breasts can increase in size by as much as 25 percent and increased blood flow to the areola – the area surrounding the nipple – causes the nipples to appear less erect. The clitoris pulls back against the pubic bone, seemingly disappearing.
The genital muscles, including the uterus and introitus, experience rhythmic contractions around 0.8 seconds apart. The female orgasm typically lasts longer than the male at an average of around 13-51 seconds.
Unlike men, most women do not have a refractory (recovery) period and so can have further orgasms if they are stimulated again.
The body gradually returns to its former state, with swelling reduction and the slowing of pulse and breathing.
The male orgasm
The following description of the physiological process of male orgasm in the genitals uses the Masters and Johnson four-phase model.
When a man is stimulated physically or psychologically, he gets an erection. Blood flows into the corpora – the spongy tissue running the length of the penis – causing the penis to grow in size and become rigid. The testicles are drawn up toward the body as the scrotum tightens.
As the blood vessels in and around the penis fill with blood, the glans and testicles increase in size. In addition, thigh and buttock muscles tense, blood pressure rises, the pulse quickens, and the rate of breathing increases.
Semen – a mixture of sperm (5 percent) and fluid (95 percent) – is forced into the urethra by a series of contractions in the pelvic floor muscles, prostate gland, seminal vesicles, and the vas deferens.
Contractions in the pelvic floor muscles and prostate gland also cause the semen to be forced out of the penis in a process called ejaculation. The average male orgasm lasts for 10-30 seconds.
The man now enters a temporary recovery phase where further orgasms are not possible. This is known as the refractory period, and its length varies from person to person. It can last from a few minutes to a few days, and this period generally grows longer as the man ages.
During this phase, the man’s penis and testicles return to their original size. The rate of breathing will be heavy and fast, and the pulse will be fast.
Unsurprisingly, given that experts are yet to come to a consensus regarding the definition of an orgasm, there are multiple different forms of categorization for orgasms.
The psychoanalyst Sigmund Freud distinguished female orgasms as clitoral in the young and immature, and vaginal in those with a healthy sexual response. In contrast, the sex researcher Betty Dodson has defined at least nine different forms of orgasm, biased toward genital stimulation, based on her research. Here is a selection of them:
- Combination or blended orgasms: a variety of different orgasmic experiences blended together.
- Multiple orgasms: a series of orgasms over a short period rather than a singular one.
- Pressure orgasms: orgasms that arise from the indirect stimulation of applied pressure. A form of self-stimulation that is more common in children.
- Relaxation orgasms: orgasm deriving from deep relaxation during sexual stimulation.
- Tension orgasms: a common form of orgasm, from direct stimulation often when the body and muscles are tense.
There are other forms of orgasm that Freud and Dodson largely discount, but many others have described them. For instance:
- Fantasy orgasms: orgasms resulting from mental stimulation alone.
- G-spot orgasms: orgasms resulting from the stimulation of an erotic zone during penetrative intercourse, feeling markedly different to orgasms from other kinds of stimulation.
Several hormones that are released during orgasm have been identified, such as oxytocin and DHEA; some studies suggest that these hormones could have protective qualities against cancers and heart disease. Oxytocin and other endorphins released during male and female orgasm have also been found to work as relaxants.