During the years when a woman can have children, her ovaries take turns each month producing a ripe egg. When the egg is released, it travels through a tube (the fallopian tube) into the uterus. A woman can get pregnant only if a sperm cell travels through the opening in the bottom of her uterus (which is called the cervix) and joins the egg. The cervix is the gateway for sperm to get into the body and for a baby passing out of the body at birth.

An egg remains fertile only for about 2 days. If a woman does not become pregnant at that time, the rich lining of the uterus that has built up over the past weeks passes through her cervix as menstrual flow. If she does become pregnant, the lining stays in place to feed the growing baby.

Hormones

The ovaries usually stop producing eggs and greatly reduce their hormone output around age 50, though the age varies from one woman to the next. This is called menopause or "the change of life". Many women fear that their sexual desire will go away with menopause. But for many women the drop in ovarian hormones does not lessen sexual desire at all.

The hormones that may help a woman feel desire are called estrogens and androgens. Androgens are thought of as "male" hormones, but women's bodies also make small amounts of androgen. About half of the androgens in women are made in the adrenal glands that sit on top of the kidneys. The ovaries make the rest of a woman's androgen.

When a woman goes through natural menopause, the adrenal glands keep making hormones. There is usually enough androgen even after the ovaries stop making it to feel sexual desire.

Most women still have a desire for sex even while their bodies are going through changes in hormone levels, such as during the menstrual cycle, pregnancy, menopause, or when taking birth control pills.

The role of estrogen

Estrogen helps keep your vagina moist and flexible, and helps it change when you are sexually aroused. When a woman is not excited, her vagina is not an open tunnel, as some think. Instead, it stays relaxed and folded together so that its walls touch each other. As a woman starts to feel aroused, the vagina gets longer and wider. The cells lining the vagina "sweat" droplets of fluid that make the vagina slippery. Changes in the vagina depend on the hormone estrogen. If a woman's estrogen levels are low, as they might be after menopause, these changes in the vagina may take place more slowly.

Without estrogen:

• Your vaginal lining thins.

• Your vaginal walls lose some of their ability to stretch.

• Your vagina may stay somewhat tight and dry, even if you are very excited. This condition is known as vaginal atrophy.

The normal pattern of female orgasm

As a woman becomes sexually excited, her nervous system sends signals of pleasure to her brain. If she is stimulated, for instance, by touching, the signals get stronger and may trigger the orgasm reflex. During orgasm, the muscles around the genitals contract in rhythm. The sudden release of muscle tension sends waves of pleasure through the genital area and sometimes over the entire body. Afterward, a woman feels relaxed and satisfied.

A woman's orgasms may change from time to time. Sometimes she may have no orgasm, or she may have one with each sexual encounter. Sometimes, she may have multiple orgasms, one after the other. As part of the natural aging process, orgasms may take longer to reach. It may also take more stimulation to achieve them.

How orgasms happen

An orgasm is a natural reflex, but most women need some experience in learning to trigger it. It is often harder to reach orgasm during intercourse than it is through the stroking of the outside genital area, usually on or near the clitoris. About 1 in 3 American women do not reach orgasm without some extra touching in addition to intercourse.

Orgasms during intercourse are not proven to be better than other orgasms. Also, orgasms where you and your partner climax at the same time may not be a realistic goal for many couples.

There are many sources of excitement that lead to orgasm. They differ for each woman. A few women can reach orgasm just by having a vivid fantasy about sex or by having their breasts stroked. Others have had an orgasm during a dream while asleep. But most women need some caressing of their genitals to reach orgasm.

The areas of a woman's genitals (see illustration) that are most sensitive to touch are the clitoris and the inner lips. The outside part of the genital area (called the vulva) includes the outer lips, inner lips, the clitoris, and the entrance to the vagina. The outer lips are filled with spongy tissue. They protect the delicate inner lips and clitoris. The opening of the urethra (the tube that carries urine from the bladder) is between the inner lips and behind the clitoris. The anus (opening of the bowels) is behind the vagina.

When a woman becomes sexually excited, the entire genital area swells. It also turns a darker pink as blood rushes in under the skin.

Many women reach orgasm most easily from stroking of the clitoris. Like a penis, the clitoris has a head and a shaft. Its function is to send messages of pleasure to the brain when it is stroked.

The head of the clitoris is so sensitive that it can become sore from direct rubbing that is either too fast or too hard. Soreness can be prevented by using lubrication and by stroking or touching close to, but not on, the head of the clitoris.

Other areas, including the outer lips and anus, can also give a woman pleasure when stroked. Each woman's sensitive zones are a little different. The opening of the vagina contains many nerve endings. It is more sensitive to light touch than the deep end of the vagina. For some women, the front wall of the vagina (stomach side) is more sensitive to pressure during sex than the back wall. Some sex therapists suggest that stroking an area about 1 to 4 inches deep on the front wall of the vagina helps some women reach orgasm during intercourse.

Last Medical Review: 11/10/2008
Last Revised: 11/10/2008