Female sexual dysfunction (FSD) is any problem that routinely interferes with a woman’s ability to achieve sexual gratification. To be considered a dysfunction, the symptoms must be persistent, pervasive and cause the woman distress. This broad definition can include difficulties with desire, arousal, orgasm and resolution. FSD includes disturbances in one or more of the response cycle phases or pain associated with arousal or intercourse.

According to the American Medical Association, approximately 43 percent of U.S. women (and 31 percent of men) have experienced some form of sexual dysfunction at some time.

FSD can start early in a woman’s life, or it may develop later in someone who previously enjoyed sex without any difficulties. The causes of sexual dysfunction can be physical, psychological or both.

Sexual activity can include fondling, masturbation, oral sex, vaginal or anal penetration and intercourse. Each woman has individual interests, responses and ways of expression that can change as she enters different life stages and as circumstances change.

The normal stages of sexual response were initially explained by a research team in a model that includes four phases:

• Excitement. Nerves are activated, increasing blood flow to the genital area. The vagina becomes lubricated, and changes begin in the labia and clitoris.
  
  
• Plateau. More changes happen in the body as the genital area builds with tension. The vagina becomes increasingly lubricated, and the upper two-thirds of the vaginal wall expand.
  
  
• Orgasm. The orgasm is a series of muscular contractions in the genital area, the uterus and vaginal walls, followed by an enormous release of muscle tension.
  
  
• Resolution. The continuation of release of muscle tension evolves into resolution, which is the final phase of pleasantly diminishing sexual tension.

In addition to the four phases described by the researchers, a woman’s sexual response is affected by her biology, psychology, sociocultural influences and interpersonal relationships. Treatment of sexual dysfunction is more likely to be successful if all these components are considered rather than just one.

In many cases, female sexual dysfunction can be categorized into four main areas, including:

• Sexual desire disorders. This includes a lack of desire for sex, sometimes referred to as a low libido.
  
  
• Sexual arousal disorders. When a woman is sexually aroused, there are physical changes that occur in the body, including an erection of the nipples, the moistening of the vagina, the relaxation of vaginal muscles and the swelling of the labia (the skin folds of the vulva) and clitoris (the small, sensitive organ above the vagina). Problems can include difficulties with any of these arousal mechanisms.
  
  
• Orgasmic disorders. An orgasm is the peak of the sexual response as the muscles of the vagina and uterus contract to create an intense pleasurable feeling.
  
  
• Sexual pain disorders. Painful intercourse (dyspareunia) can mean pain in the vagina, clitoris or labia. The pain can result from sexual stimulation, vaginal contact or penetration. Although there are many possible causes for dyspareunia, one of the most common sexual pain disorders is vulvodynia, which is the painful burning, stinging and itching of the vulva. Vaginismus is another problem that is caused when the vaginal muscles at the opening tighten as part of the sexual response. This creates dyspareunia upon penetration and can be difficult to treat. 

Women entering midlife may experience sexual dysfunction caused by menopausal changes in the body. During this period, sexual response and a general interest in sex may diminish. Changes in vaginal tissue may include thinning, dryness, itchiness or burning, and in some cases, sex may become painful (dyspareunia). However, continuing to have sex (or to masturbate) will help to keep vaginal tissue healthy after menopause. Women who have a healthy sex life before menopause will likely have a healthy one after as well.

FSD may also be caused by a chronic condition, such as severe endometriosis, or a serious illness that physically alters a woman’s body and body image, such as breast cancer or gynecologic cancer. For many women, breasts are part of their female self-image and the loss of a breast in a mastectomy, or changes in a breast’s size or shape after a lumpectomy, can sometimes cause long-term psychological and sexual problems. As many as half of all breast cancer patients experience some form of long-term sexual difficulties, according to the National Cancer Institute (NCI).

Other causes of sexual dysfunction may include, but are not limited to, minor ailments, medications and psychosocial challenges, which could include prior physical or sexual abuse.