Orgasm is the sudden discharge of accumulated sexual tension resulting in rhythmic muscular contractions in the pelvic region that produce intensely pleasurable sensations followed by rapid relaxation. Orgasm is also in part a psychological experience of pleasure and abandon, when the mind is focused solely on the personal experience. It is sometimes called climaxing or coming.
In Masters and Johnson's original research of the human sexual response cycle, orgasm is the third of four stages, occurring after the plateau phase and before the resolution phase. Another widely accepted model of the sexual response cycle, developed by Helen Singer Kaplan, M.D., PhD., involves just three stages: desire, excitement and orgasm.
Orgasms vary from person to person and for each individual at different times. Sometimes orgasm is an explosive, amazing rush of sensations, while others are milder, subtler, and less intense. The differences in intensity of orgasms can be attributed to physical factors, such as fatigue and length of time since last orgasm, as well as to a wide range of psychosocial factors, including mood, relation to partner, activity, expectations, and feelings about the experience.