Androgens: A type of sex hormone present in both women's and men's bodies. There are four types of androgens, the most common being testosterone. Androgens are produced by the ovaries, adrenal glands and other tissues. They play a key role in regulating certain body functions, including the growth spurt at puberty. They may help to regulate organ function, including the reproductive organs, kidneys, liver and muscles. During menopause, androgen levels decline, which can lead to a decreased sex drive.

Clitoris: A small organ located near the opening of the vagina that is a sensitive site of sexual excitement.

Dyspareunia: Pain during or after vaginal penetration.

Estrogen: The primary sex hormone in women's bodies. It is produced by the ovaries, adrenal glands and other tissues. Estrogen plays a key role in maintenance of many tissues throughout the body.

Female orgasmic disorder: Persistent absence or recurrent delay in orgasm after stimulation and arousal.

Female sexual dysfunction: Personal distress caused by one or more of the following symptoms associated with the sexual response cycle: lack of sexual desire, difficulty in becoming aroused, inability to achieve orgasm, anxiety about sexual performance, reaching orgasm too rapidly, pain during intercourse or failure to derive pleasure from sex.

Hormone: The body's chemical messengers. Estrogen and progestin (a synthetic form of progesterone) are the main hormones involved in the reproductive process.

Hormone therapy: (HT) Hormone therapy is used to increase hormone levels that naturally decline at menopause. It is available in two forms: HT--a combination of estrogen and a synthetic form of the hormone progesterone (progestin) -- and estrogen therapy, or ET, estrogen alone. HT is typically given to women who have not had hysterectomies because estrogen alone is known to increase the risk of uterine cancer. The addition of progestin lessens estrogen's effects on the uterine lining, thus reducing this risk. Both HT and ET are available in a variety of applications: pills, creams, skin patches, a gel, vaginal ring and injections. Because of health risks now associated with HT and ET, women and health professionals have been cautioned by the U.S. Food and Drug Administration to use the lowest effective doses of HT and ET for the shortest period possible to treat symptoms. HT is no longer considered a treatment for heart disease. HT may worsen heart disease in women who already have it and ET may increase stroke risk, though it has been shown to decrease the risk of hip fracture.

Hypoactive sexual desire disorder: Persistent, recurrent decreased or absent sexual thoughts, feelings and desire for sexual activity that cause distress or interpersonal difficulties.

Inhibited sexual desire disorder: Another name for hypoactive sexual desire disorder.

Libido: Sexual desire.

Labia: Folds of skin surrounding the opening of the vagina.

Menopause: When a woman's monthly menstrual periods end permanently, signifying the end of her childbearing years. Although the average age for menopause in the United States is 51, some women experience menopause earlier due to natural causes or following surgery, illness or that destroy ovarian function. Menopause is said to have occurred when a woman has not had a menstrual period for 12 months.

Ovaries: The pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the lower abdomen, one on each side of the uterus. These 1 1/2 inch long, walnut-shaped organs also release hormones that help to control the menstrual cycle.

Perimenopause: A transitional period of time (up to six years or more) immediately prior to natural menopause. This is the time period when women experience "menopausal" changes, such as hot flashes. The perimenopause transition also refers to the one year following menopause.

Pituitary: A gland that secretes the hormones involved with ovulation.

Progesterone: Produced by the ovaries, this reproductive hormone prepares the uterine lining for a fertilized egg to be implanted. If no egg is fertilized, progesterone levels fall, signaling the body to shed the lining and menstruation begins.

Sexual arousal disorder: Persistent or recurrent inability to reach or sustain the lubrication and swelling response in the arousal phase of the sexual response.

Sexual dysfunction: Problems in one or more of the sexual response cycle's phases, or pain associated with arousal or intercourse severe enough to cause personal distress. These may include: lack of sexual desire, difficulty in becoming aroused, inability to achieve orgasm, anxiety about sexual performance, reaching orgasm too rapidly.

Sexual response cycle: A pattern of physical and emotional responses a woman's body experiences in anticipation of and during sexual intercourse.

Testosterone: One of the androgen hormones. Though it's thought of as a "male" hormone, testosterone also is produced in smaller amounts women's bodies by the ovaries, adrenal glands and other tissues.

Vagina: A thin-walled tube about three to four inches long that lies between the bladder and rectum and extends outward from the cervix (the lip of the uterus) to the outside of the body.

Vaginismus: A sexual dysfunction in which the involuntary spasm of the muscles at the opening of the vagina make vaginal entry painful.

Vestibule: The portion of skin at the vaginal opening that contains the openings of the urethra, vagina and glands.

Vulva: The external parts of the vagina.

Vulvar vestibulitis syndrome (VVS): A form of vulvodynia (see next entry).

Vulvodynia: Vulvar discomfort, most often described as a burning pain, that exists in the absence of any clearly identifiable cause, such as an infection, cancer, or neurologic disorder like herpes or spinal nerve compression. The pain can prevent women from exercising, having intercourse, and, in extreme cases, even walking.