Overview of Female Sexual Function and Dysfunction

Female sexual dysfunction is classified into 4 subtypes in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, 5th edition, Text Revision (DSM-5-TR) (1):

• Female sexual interest/arousal disorder (formerly classified as 2 separate disorders, hypoactive sexual desire disorder and female sexual arousal disorder)

• Persistent genital arousal disorder

• Genito-pelvic pain/penetration disorder (GPPPD)

• Female orgasmic disorder

• Substance-/medication-induced sexual dysfunction 

• Pregnancy-related sexual dysfunction

The DSM-5-TR includes 2 categories for symptoms of sexual dysfunction that do not meet the full criteria for other sexual health disorders: other specified sexual dysfunction and unspecified sexual dysfunction.

In addition, a major contributor to sexual dysfunction in women who are menopausal is genitourinary syndrome of menopause.

For most people, sexual function is not static; fluctuations are natural and should be expected, especially during stressful periods of time or following major life changes. Sexual dysfunction is distinguished from sexual concerns that are not considered a dysfunction by the persistence of symptoms for at least 6 months, occurring with at least 75% of sexual encounters, and causing personal distress (1). Female sexual disorders may be secondarily categorized as lifelong or acquired; situation-specific or generalized; and mild, moderate, or severe based on the degree of distress they cause.

Almost all women with sexual dysfunction have concurrent features of more than one disorder. For example, genito-pelvic pain/penetration disorder often leads to sexual interest/arousal disorder, while reduced desire or arousal may make sex less enjoyable or even painful, decreasing the likelihood of orgasm and subsequent sexual motivation. However, pain during intercourse due to impaired lubrication may occur as an isolated symptom in women with a high level of sexual desire, interest, and subjective arousal. Although research is limited, these disorders likely affect women in heterosexual and homosexual relationships similarly.

The etiology of FSD encompasses biological, psychological, interpersonal, and sociocultural factors that contribute to chronic symptoms related to sexual pain and the 3 phases of the sexual response cycle: desire, arousal, and orgasm (see figure Biopsychosocial Model) (1, 2).

Biopsychosocial Model

Data from Parish SJ, Hahn SR, Goldstein SW, et al. The International Society for the Study of Women's Sexual Health Process of Care for the Identification of Sexual Concerns and Problems in Women. Mayo Clin Proc. 2019;94(5):842-856. doi:10.1016/j.mayocp.2019.01.009

Female Sexual Response Cycle

Historically, female sexual response was characterized as a linear model initiated as a sequence of “spontaneous” desire for sex, then “excitement,” leading to “plateau,” followed by “orgasm” and ultimately “resolution” (3).

Basson's Nonlinear Model of Sexual Responses

Data from Basson R. Using a different model for female sexual response to address women's problematic low sexual desire. J Sex Marital Ther. 2001;27(5):395-403. doi:10.1080/713846827

A more circular model, developed by Rosemary Basson and colleagues, recognizes that sexual desire may not always be spontaneous, but in many cases is “responsive” to sexual stimulation or other motivation that triggers desire and arousal, which are often difficult to distinguish from one another (see figure Basson's Nonlinear Model of Sexual Responses) (4). In addition, the Basson model recognizes the importance of emotional and physical satisfaction as important motivators for seeking and being receptive to sexual stimuli (5).

Motivation

Motivation, which is heavily influenced by biopsychosocial factors, is the wish to initiate or respond to sexual activity. There are many reasons for wanting sexual activity, including sexual interest or desire. Sexual interest or desire may be triggered by thoughts, words, sights, smells, or touch. Motivation may be obvious at the outset or may build once the woman is aroused.

Arousal

Brain areas involved in cognition, emotion, motivation, and genital sensation are activated. Neurotransmitters acting on specific receptors are involved. Based on known actions of drugs and on animal studies, some neurotransmitters appear to be prosexual; they include dopamine, norepinephrine, and melanocortin. Serotonin is usually sexually inhibitory, as are prolactin and gamma-aminobutyric acid (GABA).

Genital congestion

This reflexive autonomic response occurs within seconds of a sexual stimulus and causes genital engorgement and lubrication. The brain's appraisal of the stimulus as biologically sexual, not necessarily as erotic or subjectively arousing, triggers this response. Smooth muscle cells around blood spaces in the vulva, clitoris, and vaginal arterioles dilate, increasing blood flow (engorgement) and transudation of interstitial fluid across the vaginal epithelium (lubrication). These physiologic changes manifest in genital tingling and throbbing, which are more pronounced in younger women (6). As women age, basal genital blood flow decreases, but genital congestion in response to sexual stimuli (eg, erotica) may not.

Orgasm

Peak excitement occurs; it is accompanied by contractions of pelvic muscles every 0.8 seconds and is followed by slow release of genital congestion. Thoracolumbar sympathetic outflow tracts appear to be involved, but orgasm is possible even after complete spinal cord transection (when a vibrator is used to stimulate the cervix). Prolactin, antidiuretic hormone (ADH), and oxytocin are released at orgasm and may contribute to the sense of well-being, relaxation, or fatigue that follows (resolution). However, some women experience a sense of well-being and relaxation without experiencing any definite orgasm.

Resolution

Resolution is a sense of well-being, widespread muscular relaxation, or fatigue that typically follows orgasm. However, resolution can occur slowly after highly arousing sexual activity without orgasm. Many women can respond to additional stimulation almost immediately after resolution.

Physiology of the female sexual response is incompletely understood but involves central nervous system (CNS) and hormonal factors. Dopamine and norepinephrine are neurotransmitters found to play a major role in the sexual excitatory pathway (1). The areas of the brain responsible for desire and arousal are mediated by dopamine, while norepinephrine acts centrally to promote sexual arousal, and peripherally it influences the autonomic aspects of sexual response. Oxytocin, melanocortins, and endogenous opioids are other neurotransmitters that affect desire and arousal by modulating the intensity of the sexual response as they affect the reward centers of the brain. Oxytocin is also purported to impact intimate partner bonding.

Conversely, studies have shown, the neurotransmitter serotonin inhibits sexual desire and arousal through inhibition of the dopaminergic pathways (1). Hormones, specifically estrogens and androgens, also influence sexual response. Numerous receptors in the brain are targets for sex hormones; however, research has not been able to fully elucidate the underlying mechanism pertaining to sexual function. While evidence from some studies supports the claim that estradiol is central to modulation of sexual desire, other animal trials demonstrate testosterone’s impact on the dopaminergic pathways in the prefrontal cortex. Benefit of testosterone supplementation in postmenopausal women with sexual dysfunction in clinical trials has also been shown (2).

Peripherally, the interplay between sex steroid hormones and adrenergic signaling influences the female sexual response by regulating sex steroid receptors in the genitourinary tissues including the pelvic floor support muscles, maintenance of genitourinary tissues and function, and production of vaginal lubrication (2).  Specifically, estrogen helps maintain genital tissue sensitivity, vaginal pH, normal microflora, elasticity, lubrication, urinary continence, and pelvic muscle tone.

After menopause, ovarian estrogen production ceases, while ovarian androgen production varies. However, adrenal production of prohormones (eg, dehydroepiandrosterone sulfate [DHEAS]) that are converted to both androgens and estrogens in peripheral cells decreases starting in a woman's 30s. Ovarian production of prohormones further declines after menopause. Overall, levels of androgen tend to stop decreasing at about age 60. While declining sex hormones after menopause clearly contributes to bothersome genitourinary symptoms, the role of hypoestrogenism in diminishing sexual desire, interest, or subjective arousal is unclear (3).

The brain produces sex hormones (neurosteroids) from cholesterol, and production may increase after menopause. Whether this documented increase is universal, whether it facilitates arousal as peripheral production decreases, and whether it is affected by exogenous hormone administration are all unknown.

• Interview with the woman and, sometimes, her partner

• Pelvic examination

Female sexual dysfunction is common, and incorporating screening into routine clinical practice helps reduce any related stigma and provides help to patients who may be reluctant to initiate discussions of these issues. Numerous tools have been created to aid in the screening process; however, starting with a simple statement that acknowledges the normalcy and commonality of female sexual dysfunction, followed by inquiring about specific sexual concerns, is easy and effective (1, 2). (See table Examples of Two-Part Ubiquity Statements.)

Diagnosis of sexual dysfunction is based on history and physical examination. Both the history and physical examination may detect issues that cause or contribute to sexual function symptoms.

Sexual dysfunction disorders are classified based on clinical criteria described by the DSM-5-TR (3). These disorders include genito-pelvic pain/penetration disorder, female orgasmic disorder, female sexual interest/arousal disorder, and substance-/medication-induced sexual dysfunction (see Classification). For diagnosis of these disorders, there must be no more likely alternative explanation for symptoms. With the exception of substance-/medication-induced sexual dysfunction, symptoms must have been present for 6 months to be considered a disorder.

Evaluation of female sexual dysfunction requires a focused sexual history informed by the biopsychosocial model and a physical examination.

Important components of the history include (1, 4, 5):

• Assess each sexual response cycle domain (desire, arousal, orgasm) and presence and type of symptoms

• Specify timeline of onset of symptoms; determine whether sexual concerns are acquired or have been present for the patient's entire sexual history

• Assess the situational versus generalized nature of symptoms

• Inquire about contributing biological, psychological, sociocultural and interpersonal factors (see figure Biopsychosocial Model)

• Rate degree of distress: mild, moderate, or severe

See table Components of the Sexual History for Assessment of Female Sexual Dysfunction for a detailed outline of the key components of the sexual history.

The physical examination is an important part of the clinical evaluation of female sexual dysfunction. Understanding the anatomy of the pelvic floor and the interplay between muscles, innervation and blood flow is critical to a comprehensive examination. Involving the patient in the evaluation through the aid of a mirror often helps identify location of pain or other symptoms (1). Explaining what will occur throughout the examination helps reduce anxiety and increase relaxation.

The external genitalia are inspected for evidence of vaginitis, dermatitis, dermatoses, hypoestrogenism, neoplasm, or trauma. The assessment also involves checking for voluntary muscle contraction, relaxation, or spasms. Although concerns around specificity have been raised, the cotton swab test is often used to test for vulvodynia, by gently touching the vestibule with a moist cotton swab in a systematic pattern to localize pain. An internal vaginal examination including a speculum examination is performed to assess the vaginal mucosa and the cervix, and to detect vaginal or cervical discharge. Bimanual palpation is performed to assess overall size, position, and tenderness of the uterus, and for adnexal pathology (2).

For women who have undergone hysterectomy with or without removal of the ovaries, the pelvic examination is still important to evaluate for pelvic masses or for evidence of pelvic organ prolapse.

Additional workup with laboratory assessment, biopsy, and imaging is generally not needed to identify etiology of sexual dysfunction, but it may be necessary if indicated by history or examination findings (4, 6). Laboratory testing can be helpful in some cases but is not consistently useful for diagnosis or to guide treatment. (See table Indications for Laboratory Testing in Diagnosis or Treatment of Female Sexual Dysfunction). If a vulvar dermatosis is suspected, a vulvar biopsy should be performed, especially if the patient fails presumptive treatment. Pelvic ultrasound is sufficient for evaluation of most patients with pain triggered by thrusting with vaginal penetration; however, if a neurologic etiology is suspected, an MRI of the lumbar sacral spine is indicated.

• Treatment of underlying causes

• Prescribing medications to treat sexual dysfunction, or adjusting or discontinuing medications with sexual side effects

• Pelvic floor physical therapy

• Personal or couple's psychotherapy or sex therapy

Treatment of sexual dysfunction in women depends upon the domain of sexual function (eg, interest, orgasm), whether underlying causes can be identified and treated, and the goals of the patient. Sexual dysfunction is typically managed with a multidisciplinary approach.

Medical and psychosocial issues that impact sexual function should be addressed.

First-line management of sexual dysfunction is usually with conservative approaches. For some issues, pharmacologic therapies are available. Patients should be appropriately counseled about these, including efficacy and potential adverse effects. Patients may benefit from sex therapy and individual or couple's psychotherapy. In addition, women may be referred to pelvic floor physical therapy to address musculoskeletal dysfunction and/or pain predominant presentations.