A Healthy Bladder

A Consensus Statement

E. S. Lukacz; C. Sampselle; M. Gray; S. MacDiarmid; M. Rosenberg; P. Ellsworth; M. H. Palmer


Int J Clin Pract. 2011;65(10):1026-1036. 

In This Article


Understanding Bladder Anatomy

Understanding the anatomy and physiology of the urinary system and what constitutes a healthy bladder, including its function, anatomy and potential susceptibility to dysfunction, may help promote bladder health. The bladder is a hollow muscular organ that is lined by mucosa (urothelium) and is sensitive to both urine volume and its chemical composition (Figure 1A–C). The kidneys filter blood to remove excess water and waste products and produce urine, which travel from the kidneys to the bladder through the ureters. Urine is stored in the bladder until it is emptied through the urethra. The bladder neck, external urethral sphincter and the pelvic floor muscles help to maintain continence.

Figure 1.

Urinary system (A) frontal view (woman), (B) lateral view (woman) and (C) lateral view (man)

Healthy Bladder Functioning

A healthy bladder is free of bacterial infection or tumours and stores urine without discomfort at low pressure with intermittent signals of filling.[57] Normal functional bladder capacity in adults ranges from approximately 300 to 400 ml.[58,59] Although the International Continence Society defines urinary frequency as the perception by the patient that he/she voids too often,[1] epidemiological studies suggest that the normal micturition rate is approximately 8 micturitions per day and 1 or fewer episodes per night.[60] As such, small volumes with increased micturition frequency suggest abnormality. Nerve fibres respond to increasing filling, and micturition is prompted at or near bladder volume capacity (approximately every 3–4 h based on volume of liquid consumed). Voiding typically occurs via initial relaxation of the pelvic floor muscles and the bladder neck followed by voluntary contraction of the detrusor muscle. Healthy voiding occurs promptly with strong continuous flow and complete emptying without pain or blood in the urine. When necessary, an individual should be able to defer voiding without leakage. Variations in any of these normal responses may be a sign of disease.

Knowledge of the physical and functional aspects of the bladder may help promote bladder health, as well as treatment outcomes for bladder conditions. For example, pelvic floor muscle exercises (also known as Kegel exercises) may prevent and treat mild stress incontinence.[61–63] Many individuals with OAB who were successfully treated with a combination of behavioural interventions plus an antimuscarinic after failing previous antimuscarinic therapy cited information provided to them about the bladder and pelvic floor muscles as an important contributor to their treatment satisfaction.[64] It is anticipated that increasing knowledge about changes in bladder health/function over time will help adults to identify and seek treatment for bladder conditions. Anatomically, functional bladder capacity increases with age from childhood [(years of age + 2) × 30 ml] to adulthood (300–400 ml). Changes in the adult bladder and pelvic floor muscles with ageing also include decreased bladder sensation, decreased contractility during voiding, decreased muscle tone in pelvic floor muscles and increased residual volume (57,65–70). Other physical changes include up-regulation of purinergic receptors with increased prevalence of detrusor overactivity[71] and increased acetylcholine release in the urothelium,[71] both of which can produce LUTS. The prevalence of LUTS increases with age.[4] While there are age-associated changes to the bladder and its function, those effects are minimal and easily compensated for by changes in bladder habits. Troublesome or severe bladder symptoms are not normal; therefore, the false belief that incontinence, for example, is a natural, inevitable consequence of ageing should be dispelled.[72]

Influences on Bladder Function

Dietary Influences A number of factors influence bladder function (Figure 2). For example, some foods and beverages may provoke bladder urgency or discomfort or stimulate diuresis, including caffeine, carbonated beverages and artificial sweeteners.[73–77] Several types of beverages and foods, including coffee, tea, soda, alcoholic beverages, citrus fruits and juices, artificial sweeteners and hot peppers can exacerbate symptoms in patients with BPS/IC.[78] The BPS/IC Ad Hoc Committee on Diet has published a list of 'bladder- and prostate-friendly foods' with the intent of helping people determine and avoid foods that may trigger symptoms or compromise treatment efficacy[79] and AUA BPS/IC guidelines suggest avoidance of foods and beverages which are known to be bladder irritants, such as coffee and citrus products. The guideline also suggests using an elimination strategy to identify foods that may cause or exacerbate symptoms.[2] Fluid intake may also affect bladder function. Based on 3-day diary entries, fluid intake averaging > 3700 ml per day has been associated with voiding frequency of > 10 times during the day and nearly 2 times at night, as well as higher incidence of UI, compared with intake of approximately 2400 ml per day.[80] Some people may limit fluid intake as a way to cope with LUTS, including urgency, frequency and UI.[81–83] However, fluid restriction may increase urine concentration, leading to irritation of the bladder mucosa and increased incidence of LUTS and UTI.[84] The US Food Science Board recommended that fluid intake volume is 30 ml/kg per day or half an ounce per pound per 24 h.

Figure 2.

Factors influencing bladder health

Pelvic Floor Functioning Healthy pelvic floor function is important to having a healthy bladder. Pelvic floor muscle training can be used to alleviate UI and urgency and to extend the interval between voids.[85] Strengthening or learning to contract pelvic floor muscles may also increase the efficacy of pharmacotherapy.[85,86] In a randomised clinical trial, pelvic floor muscle training, pre-emptive pelvic floor contraction to prevent leakage and bladder training significantly decreased UI and voiding frequency 12 months postintervention.[87] In another study, education about pre-emptive pelvic floor muscle contraction to prevent leakage (the Knack maneuver) significantly reduced UI in older women and pregnant women.[88] A systematic review assessing the effect of pelvic floor muscle training versus standard antenatal and postnatal care concluded that pelvic floor muscle training may prevent UI in late pregnancy and postpartum and may effectively reduce persistent postpartum UI.[89] Timed voiding has also been employed with and without other behavioural interventions for managing UI.[90] A test of education about bladder training, pelvic floor muscle training and the Knack maneuver is currently in progress to assess the preventive impact of these combined behavioural interventions.

Adult and Childhood Toileting Habits Toileting behaviours related to urination can contribute to dysfunctional voiding habits. Identifying and modifying the various components of voiding, including place, time, position and style, may help prevent, eliminate, reduce and/or manage LUTS.[91] Furthermore, toilet training rituals during childhood may affect bladder health in adulthood[92] and childhood urinary symptoms are significantly associated with adult bladder conditions.[93,94] An association has also been reported between OAB symptoms in children and their birth parents, with the fathers having stopped 'bed wetting' at a significantly later age than the fathers of children without OAB and mothers of children with OAB having similar symptoms in childhood compared with mothers of children without OAB.[95]

Societal Attitudes Social/cultural attitudes may influence the response to or perception of bladder function and may interfere with treatment-seeking behaviour. LUTS such as increased voiding frequency and urgency are associated with social limitation, loss of control of the body and speculation as to the nature of a non-specific 'problem'.[96] UI and other LUTS are associated with reduced HRQL, stigma and embarrassment.[28,96–98] Bladder conditions may interfere with cultural/religious rituals, resulting in underreporting. For example, Jewish and Muslim religions require an element of cleanliness for prayer that is compromised by the perceived lack of cleanliness associated with urinary incontinence.[99]

Environmental Influences Environmental factors can also influence bladder health. Work environments are required to provide adequate access, cleanliness and safety for toilet facilities;[100] lack thereof can cause decreases in liquid intake[101] or infrequent voiding[102] by workers that can lead to compromised bladder function or urinary tract infection. Occupational barriers exist for individuals with paruresis,[103] who experience social anxiety associated with travel, work or interpersonal relationships associated with the fear of being unable to urinate in the presence of others. In addition, attitudes and rules regarding toileting in school may influence bladder habits. Teachers' awareness of factors that contribute to bladder dysfunction in school-aged children is important.[104,105] Lack of awareness among teachers regarding normal elimination patterns in children can lead to restrictions on the frequency of children's access to bathroom facilities, which may have adverse effects on bladder health.[104] In addition, the bathrooms in schools are reportedly often lacking in privacy, cleanliness and safety (e.g. a place where bullying may occur), which may contribute to urine-holding behaviours and dysfunctional voiding.[104,106]

Physical Factors Physical influences on bladder health are less understood. Bladder conditions can vary based on age, gender, health history[107,108] and ethnicity.[109–111] For instance, it is well established that the prevalence of all categories of LUTS increase with age in men and women.[4,112] Moreover, there are differences between men and women in the LUTS that they are likely to experience and in the bother associated with LUTS.[113–116] In the EPIC study, a population-based, cross-sectional survey of UI, OAB and other LUTS among people in five countries, the prevalence of storage LUTS tended to be greater in women (59% vs. 51%), whereas the prevalence of voiding (26% vs. 20%) and postmicturition (17% vs. 14%) LUTS tended to be higher in men.[4] Men may be more likely to experience bother associated with UI than women.[117]

UTI is more prevalent in women than men[118] and a variety of factors affecting UTI in women may be related to age. For example, in women, postmenopausal status, sexual activity, history of UTI, treated diabetes and UI are associated with a higher risk of UTI.[119,120] UTI in postmenopausal women has been linked to several factors/conditions that are associated with a decrease in oestrogen, including vaginal prolapse, elevated postvoid residual urine volume and urinary incontinence. Treatment with oestrogen results in increased glycogen production in the vaginal tissues providing an acidic environment for lactobacilli and other normal pathogens to thrive. Low oestrogen levels result in alterations in pH and promotion of growth of enteric bacteria associated with UTI. Treatment with vaginal oestrogen vs. placebo has shown promise for utilisation of oestrogen for reducing the incidence of recurrent UTI.[121] At clinical presentation, postmenopausal women are more likely than younger women to report flank pain, whereas younger women are more likely than postmenopausal women to report frequency, dysuria, haematuria and fever.[122] BPS/IC may also be more prevalent in women than in men.[123] Bladder cancer is more prevalent in men than in women and the risk of bladder cancer increases with age in both genders.[13]

Concomitant Conditions Bladder health may also be influenced by secondary effects of pregnancy[124] and childbirth[124–127] and by a number of conditions or comorbidities, such as obesity,[128,129] diabetes,[130] hypertension/heart failure[101,130] and constipation. Furthermore, patients may have comorbidities that are not only reportedly associated with increased rates of incontinence but increase the difficulty of managing UI symptoms.[131] For example, dementia has been shown to be an independent predictor of UI.[132] In addition, many medications prescribed for comorbidities (e.g. sympathomimetics, tricyclic antidepressants, α-adrenergic blockers and angiotensin converting enzyme inhibitors) may affect continence.[133] Although urinary incontinence is prevalent in patients with heart failure and/or comorbid diabetes, patients vary with regard to health-seeking behaviours to address urinary incontinence thereby requiring different types/levels of education.[130] Obesity is associated with LUTS, including stress, mixed and urgency UI.[128,134,135] Likewise, weight loss is associated with improvements in incontinence status.[128,136] Although the exact mechanisms linking the two conditions has not been completely elucidated, results of the Program to Reduce Incontinence by Diet and Exercise (PRIDE) study indicate an association between BMI and abdominal circumference with intra-abdominal and intravesical pressure.[137] Shared neural pathways for the bladder and bowel may play a role in OAB symptoms;[138,139] individuals with constipation are more likely to develop OAB symptoms than those who are not constipated.[140] Furthermore, constipation and OAB are associated with uterovaginal prolapse; in a study of 320 women with LUTS (40% with OAB), 16% had faecal incontinence (FI) and 32% had constipation.[141] Finally, bladder cancer is more common in individuals with a history of smoking, exposure to aniline dyes, history of chronic bladder inflammation, prior pelvic irradiation (such as for prostate cancer or gynaecological malignancies), chemotherapy with cyclophosphamide (cytoxan) or ifosfamide (ifex) and in those with chronically low fluid consumption.

Conversely, there may be collateral physical benefits of enhanced bladder health. The increased risk of falls and fractures in patients with OAB or urgency UI is thought to be largely attributable to the act of rushing to the bathroom. Thus, treatment of OAB and UI may be associated with decreased fall risk.[35,142,143] Additional benefits of healthy bladder habits may include improved sexual function. Enhanced sexual pleasure is most plausibly linked to greater pelvic muscle strength and control ensuing from an exercise regimen recommended to reduce UI. Research is sparse, but results of two studies provide some support. Midlife women with stress UI who completed a 6-month programme of pelvic floor muscle training reported fewer problems with sexual dysfunction related to UI.[144] Midlife women who completed a 12-month programme of pelvic floor muscle training reported significantly higher levels of sexual satisfaction compared with controls.[145]

An important modifiable behaviour associated with poor bladder health is smoking. There are strong associations between smoking and LUTS[146–149] and the risk of bladder cancer has been reported to be increased twofold in smokers with an increase in risk with increasing amounts of smoking[150] and longer duration.[151] In addition, smoking cessation has positive impact on overall health and related quality of life and should universally be encouraged.

Potential Benefits of the Consensus Statement on Bladder Health

This statement is intended to raise awareness of bladder health by stimulating discussion on this topic and primary prevention research in the form of epidemiological studies, educational needs assessment and community-based public health initiatives. Primary preventions are intended to prevent expected health problems, to maintain existing states of health and healthy functioning and to promote desired outcomes.[56,152] Thus, initiatives that disseminate information about healthy bladder function may give rise to adoption of practices that promote bladder health.

The desired outcome of increased awareness of healthy bladder habits is a reduction in negative outcomes associated with bladder conditions including nursing home admittance, falls and impaired HRQL.[17,35,142,143] Individuals with healthy habits may still develop bladder conditions; however, knowledge of the physical and functional aspects of the bladder may help mitigate the sequelae of underreported, underdiagnosed and undertreated bladder symptoms. Identification and awareness of risk factors, including smoking and obesity, is likely to be an important part of primary prevention of bladder conditions. In addition, bladder health education may increase screening for bladder cancer, BPS/IC, early and transient UI and UTIs, for which some diagnoses are ambiguous. For BPS/IC in particular, there remains a lack of consensus on diagnosis based on the lack of a diagnostic instrument to accurately diagnose the condition, which may be attributable at least in part to the overlap in symptomatology, including pelvic pain and UI, with various other conditions (e.g. fibromyalgia, endometriosis, irritable bowel syndrome and recurrent UTIs).[5] Education, however, should improve outcomes and/or perceptions about bladder health. A study evaluating the effect of an education intervention, including information about OAB, medication use and behavioural therapy, demonstrated that adherence to behaviour modification therapies and self-perception of treatment outcome were significantly enhanced compared with controls.[153] Adherence with a self-management practice such as pelvic floor muscle training has been associated with adherence to bladder training as well.[154]

Many people with bladder conditions tend not to report related symptoms to healthcare providers and use multiple coping mechanisms as opposed to seeking professional treatment.[155] Various health risks are associated with avoidance of healthcare seeking, including UI progression and recurrence of UTI.[155] Men and women vary with regard to perception of bother and healthcare-seeking behaviours.[113] Raising awareness can help reduce the stigma associated with bladder conditions, which is a barrier to bladder health that can compromise outcomes and reduce HRQL.[156] Improving the basic understanding of normal bladder function and treatment options for conditions/disease may result in increased care-seeking behaviours. Education can help reduce the stigma associated with LUTS.[96] Increasing physician, nurse practitioner and physician assistant education about the importance of bladder health may also increase clinician engagement by combating various barriers to clinician involvement (e.g. limited reimbursement for prevention, lack of clinician training, etc.).

An anticipated benefit from this consensus statement is to raise awareness among the Public Health world regarding bladder health in the context of overall health, to help lay the ground work for a world-wide public health initiative.[157] One limitation of this initial statement is that it is based on the US perspective, because, globally, the impact of the influencers will vary. In addition, the authors of this statement acknowledge gaps in the available literature. Lastly, the authors of this statement do not intend it to be a comprehensive review of all data related to bladder health.


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