Orgasm (from Greek ὀργασμός, orgasmos; "excitement, swelling") or sexual climax (or simply climax) is the sudden release of accumulated sexual excitement during the sexual response cycle, characterized by intense sexual pleasure resulting in rhythmic, involuntary muscular contractions in the pelvic region. Orgasms are controlled by the involuntary or autonomic nervous system and experienced by both males and females; the body's response includes muscular spasms (in multiple areas), a general euphoric sensation, and, frequently, body movements and vocalizations. The period after orgasm (known as the resolution phase) is typically a relaxing experience after the release of the neurohormones oxytocin and prolactin, as well as endorphins (or "endogenous morphine").
Human orgasms usually result from physical sexual stimulation of the penis in males (typically accompanied by ejaculation) and of the clitoris (and vagina) in females. Sexual stimulation can be by masturbation or with a sexual partner (penetrative sex, non-penetrative sex, or other sexual activity). Physical stimulation is not requisite though, as possibilities exist to reach orgasm through psychological means alone. And getting to orgasm may be difficult without a suitable psychological state. During sleep, a sex dream can trigger an orgasm and the release of sexual fluids.
The health effects surrounding the human orgasm are diverse. There are many physiological responses during sexual activity, including a relaxed state, as well as changes in the central nervous system, such as a temporary decrease in the metabolic activity of large parts of the cerebral cortex while there is no change or increased metabolic activity in the limbic (i.e., "bordering") areas of the brain. These effects affect cultural views of orgasm, such as the beliefs that orgasm (and the frequency or consistency of it) is either important or irrelevant for satisfaction in a sexual relationship, and theories about the biological and evolutionary functions of orgasm. There are also sexual dysfunctions involving orgasm, such as anorgasmia.
