Has your sex life lost some of its spark because your body feels unresponsive or you're just not interested? You might take comfort in knowing that as many as four in 10 women have the same problem at some point in their lives.

If you have persistent or recurrent problems with sexual response — and if these problems are making you distressed or straining your relationship with your partner — what you're experiencing is known medically as female sexual dysfunction.

Female sexual dysfunction has many possible symptoms and causes. Fortunately, they're almost all treatable. Communicating your concerns and understanding your anatomy and your body's normal response to sexual activity are important steps toward gaining sexual satisfaction.

You can develop female sexual dysfunction at any age, but sexual problems are most common when your hormones are in flux — for example, when you've just had a baby or when you're making the transition into menopause. Sexual concerns may also occur with major illness, such as cancer.

Your problems might be classified as female sexual dysfunction if you experience one or more of the following and you're distressed about it:

• Your desire to have sex is low or absent.
• You can't maintain arousal during sexual activity, or you don't become aroused despite a desire to have sex.
• You cannot experience an orgasm.
• You have pain during sexual contact.

Several factors may contribute to sexual dissatisfaction or dysfunction. These factors tend to be interrelated.

• Physical. Physical conditions that may cause or contribute to sexual problems include arthritis, urinary or bowel difficulties, pelvic surgery, fatigue, headaches, other pain problems, and neurological disorders such as multiple sclerosis. Certain medications, including some antidepressants, blood pressure medications, antihistamines and chemotherapy drugs, can decrease your sex drive and your body's ability to achieve orgasm.

• Hormonal. Lower estrogen levels during the menopausal transition may lead to changes in your genital tissues and your sexual responsiveness. The folds of skin that cover your genital region (labia) become thinner, exposing more of the clitoris. This increased exposure sometimes reduces the sensitivity of the clitoris, or may cause an unpleasant tingling or prickling sensation.

  In addition, the vaginal lining becomes thinner and less elastic, particularly if you're not sexually active. At the same time, the vagina requires more stimulation to relax and lubricate before intercourse. These factors can lead to painful intercourse (dyspareunia), and achieving orgasm may take longer.

  Your body's hormone levels also shift after giving birth and during breast-feeding, which can lead to vaginal dryness and can affect your desire to have sex.

• Psychological and social. Untreated anxiety or depression can cause or contribute to sexual dysfunction, as can long-term stress. The worries of pregnancy and demands of being a new mother may have similar effects. Longstanding conflicts with your partner — about sex or any other aspect of your relationship — can diminish your sexual responsiveness as well. Cultural and religious issues and problems with your own body image also may contribute.

  Emotional distress can be both a cause and a result of sexual dysfunction. Regardless of where the cycle began, you usually need to address relationship issues for treatment to be effective.

If sexual problems are undermining your relationship or disrupting your peace of mind, make an appointment with your doctor for evaluation.

You might be reluctant to consult your doctor about sexual concerns, but your sexuality is integral to your well-being — and it's standard practice during general medical visits for doctors to ask about sexual health. The more forthcoming you can be about your sexual history and current problems, the better your chances of finding an effective approach to treating them.

You may need a pelvic exam, during which your doctor will check for any physical changes that may be diminishing your sexual enjoyment, such as thinning of your genital tissues, decreased skin elasticity, scarring or pain.

Your doctor may also refer you to a counselor or therapist specializing in sexual and relationship problems.

Female sexual dysfunction is generally divided into the following four categories, which are not mutually exclusive:

• Low sexual desire. You have diminished libido, or lack of sex drive.
• Sexual arousal disorder. Your desire for sex might be intact, but you have difficulty or are unable to become aroused or maintain arousal during sexual activity.
• Orgasmic disorder. You have persistent or recurrent difficulty in achieving orgasm after sufficient sexual arousal and ongoing stimulation.
• Sexual pain disorder. You have pain associated with sexual stimulation or vaginal contact.

Sexual response is a complex interaction of many components, including physiology, emotions, experiences, beliefs, lifestyle and relationships. If any one of these components is disrupted, sexual drive, arousal or satisfaction may be affected.

Women with sexual concerns benefit from a combined treatment approach that addresses medical as well as emotional issues. Occasionally, there's a specific medical solution — using vaginal estrogen cream, for example, or switching from one antidepressant medication to another. More often, behavioral treatments — such as couple's therapy and stress management — are needed to address the roots of female sexual dysfunction. And sometimes, a combination approach works best.

Nonmedical treatment for female sexual dysfunction
You can improve your sexual health by enhancing communication with your partner and making healthy lifestyle choices.

• Talk and listen. Some couples never talk about sex, but open and honest communication with your partner can make a world of difference in your sexual satisfaction. Even if you're not used to communicating about your likes and dislikes, learning to do so and providing feedback in a nonthreatening manner can set the stage for greater sexual intimacy.
• Practice healthy lifestyle habits. Avoid excessive alcohol. Drinking too much will blunt your sexual responsiveness. Also, stop smoking and start exercising. Cigarette smoking restricts blood flow throughout your body, and less blood reaching your sexual organs means decreased sexual arousal and orgasmic response. Regular aerobic exercise can increase your stamina, improve your body image and elevate your mood, helping you feel more romantic, more often. Finally, don't forget to make time for leisure and relaxation. Learning to relax amid the stresses of your daily life can enhance your ability to focus on the sexual experience and attain better arousal and orgasm.

• Strengthen pelvic muscles. Pelvic floor exercises can help with some arousal and orgasm problems. Doing Kegel exercises strengthens the muscles involved in pleasurable sexual sensations. To perform these exercises, tighten your pelvic muscles as if you're stopping your stream of urine. Hold for a count of five, relax and repeat. Do these exercises several times a day.

  Your doctor also may recommend exercising with vaginal weights — a series of five weights, each increasingly heavier, that you hold in place in your vagina — to strengthen pelvic floor muscles. You gradually work up to heavier weights as your muscle tone improves.

• Seek counseling. Talk with a counselor or therapist specializing in sexual and relationship problems. Therapy often includes education about normal sexual response, ways to enhance intimacy with your partner, and recommendations for reading materials or couples exercises. With a therapist's help, you may gain a better understanding of your sexual identity, beliefs and attitudes; relationship factors including intimacy and attachment; communication and coping styles; and your overall emotional health.

Medical treatment for female sexual dysfunction
Effectively treating sexual dysfunction often requires addressing an underlying medical condition or hormonal change that's affecting your sexuality.

Treating female sexual dysfunction tied to an underlying medical condition might include:

• Adjusting or changing medications that have sexual side effects
• Treating thyroid problems or other hormonal conditions
• Optimizing treatment for depression or anxiety
• Strengthening pelvic floor muscles
• Trying strategies recommended by your doctor to help with pelvic pain or other pain problems

Treating female sexual dysfunction linked to a hormonal cause might include:

• Estrogen therapy. Localized estrogen therapy — in the form of a vaginal ring, cream or tablet — can improve sexual function in a number of ways, including improving vaginal tone and elasticity, increasing vaginal blood flow, enhancing lubrication, and having a positive effect on brain function and mood factors that impact sexual response.
• Progestin therapy. In some research studies, women taking progestins experienced a decrease in sexual desire and vaginal blood flow. However, in other studies, women experienced improvements in desire and arousal when they took progestin in addition to estrogen. More studies are under way to see if different progestin regimens, alone or in combination with estrogen and other hormonal agents, may benefit sexual function. Progestins generally are prescribed to balance estrogen's effect on the uterus and not to treat female sexual dysfunction.

• Androgen therapy. Androgens include male hormones, such as testosterone. Testosterone is important for sexual function in women as well as men, although testosterone occurs in much lower amounts in a woman. Androgen therapy for sexual dysfunction is controversial. Some studies show a benefit for women who have low testosterone levels and develop sexual dysfunction, other studies show little or no benefit.

  Testosterone may be given as a cream or gel patch applied to your skin. Sometimes, testosterone is given as a pill or injection. Side effects, such as acne, excess body hair (hirsutism), enlargement of the clitoris, and mood or personality changes, are possible. Because long-term effects of testosterone therapy in women aren't known, you should be closely monitored by your doctor.

Hormonal therapies won't resolve sexual problems that have causes unrelated to hormones. Because the issues surrounding female sexual dysfunction are usually complex and multifaceted, even the best medications are unlikely to work if other emotional or social factors remain unresolved.

Emerging treatments
Tibolone is a drug currently used in Europe and Australia for treatment of postmenopausal osteoporosis. In a small study, women taking the drug experienced an increase in vaginal lubrication, arousal and sexual desire. But Tibolone hasn't yet received Food and Drug Administration (FDA) approval for use in the U.S.

At each stage of your life, you may experience changes in sexual desire, arousal and satisfaction. Accepting these changes and exploring new aspects of your sexuality during times of transition contribute to positive sexual experiences.

Understanding your body and what makes for a healthy sexual response can help, too. The more you and your partner know about the physical aspects of your body and how it works, the better able you'll be to find ways to ease sexual difficulties. Ask your doctor about how things like aging, illnesses, pregnancy, menopause and medicines might affect your sex life.

Sexual response often has as much to do with your feelings for your partner as it does with physical sexual stimuli. For women, emotional intimacy tends to be an essential prelude to sexual intimacy. Show affection and communicate openly with your partner about your feelings — it can help you reconnect and discover each other again.

To learn more about your body and how to communicate with your partner, check out these books:

• "Hot Monogamy: Essential Steps to More Passionate, Intimate Lovemaking," by Patricia Love, M.D., and Jo Robinson
• "Resurrecting Sex: Solving Sexual Problems & Revolutionizing Your Relationship," by David Schnarch, Ph.D.
• "What Your Mother Never Told You About S-e-x," by Hilda Hutcherson, M.D.
• "Sex Over 40," by Saul H. Rosenthal, M.D.