Orgasm 101: Masters and Johnson Helps Explain What Actually Happens During An Orgasm

Much of what we know about the human body during orgasm is thanks to the groundbreaking sex therapists and researchers Masters and Johnson. The two created the phrase “sexual-response cycle” to describe the four phases of an orgasm that the human body experiences—excitement, plateau, orgasm and resolution. Of course, the phases are not actually distinct and can vary from individual to individual, but the four phases Masters and Johnson defined give us a starting point and a way of understanding what happens to our bodies during an orgasm.

The Phases of an Orgasm

The first phase, excitement, is entered into with 10 to 30 seconds of any erotic stimulation. For men, the penis and/or the nipples will start to become erect. For women, the phase is marked by the beginning of lubrication in the vagina, as well as an expansion and lengthening of the vagina. For both men and women, heart rate, breathing and blood pressure will increase.

During the plateau phase, men become fully erect, and women experience increased puffiness of the vaginal lips. Both may experience a sex flush on the torso or face, as well as tensing muscles in the hands and lower body.

The third phase is the shortest. Semen is ejaculated from the penis for men, and women’s vaginal walls contract. This is the shortest of the four phases. Men’s orgasms last 10 seconds, while women’s go on for 20 seconds or longer with the possibility of multiple orgasms for women.

During resolution, the final phase, the body returns to its normal resting state. For both men and women, swelling diminishes, any sexual flush goes away and there is a general sense of muscle relaxation. A man’s penis returns to its normal state, while the clitoris and uterus in a woman return to their normal positions as well.

Why Orgasms Feel Good

If an orgasm didn’t feel good, we wouldn’t all be so interested in them, would we? So what exactly happens during an orgasm that produces such positive sensations? To start with, your brain’s activity clears the way for your body to send large quantities of dopamine to it. In case you haven’t heard, dopamine is a chemical our body produces that unleashes sensations associated with pleasure. Dopamine however is not responsible for the actual pleasure people feel with orgasm, it merely lets us anticipate the sensation.

In all, three parts of the brain are involved— the insula, the anterior cingulate, the ventral striatum and the hypothalamus—when humans orgasm. Meanwhile other parts of the brain that control our fears and awareness of the world show a decrease in activity. Compiled <>together, these changes in brain function work in concert to create a state where the body is focused on experiencing pleasure.