Urinary incontinence

Last updated: March 24, 2022

Summary

Urinary incontinence is a common condition characterized by uncontrollable leakage of urine. Causes and presentations are variable. Stress incontinence, urge incontinence, and mixed incontinence are the most frequent forms. Urinary incontinence remains a grossly underreported condition in the US, affecting approximately 30–40% of the adults older than 65 years of age. The condition is twice as common in women as men. Diagnosis involves a detailed medical history, a voiding diary, physical examination, and diagnostic testing such as measurement of the bladder pressure (urodynamic examination). Treatment is determined based on the type of incontinence and its etiology, and usually involves measures such as pelvic floor physiotherapy, anti-incontinence devices, anticholinergics, or collecting devices. The prognosis in adequately treated cases is usually excellent, but, if left untreated, constant contact with leaked urine can cause urinary tract infections, dermatitis, and psychological distress.

Osmosis: Urinary incontinence - causes, symptoms, diagnosis, treatment, pathology

Epidemiology

Prevalence ^[1]
- Increases with age
- Up to 50% of women and up to 25% of men older than 65 years are affected.
Sex: ♀ > ♂ (2:1) ^[2]
- Stress incontinence and mixed incontinence are the most common types of incontinence in female patients.
- Urge incontinence is the most common type in male patients.

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Idiopathic
Neurological causes
- Multiple sclerosis
- Spinal injury
- Normal-pressure hydrocephalus
- Dementia
- Delirium
Genitourinary causes
- Trauma to the pelvic floor
- Intrinsic sphincter deficiency
- Urethral hypermobility in women
- Impaired detrusor contractility
- Bladder outlet obstruction
- Pelvic floor weakness
- Urogenital fistula
Potentially reversible causes
- Drugs (e.g., diuretics)
- Urinary tract infections
- Postmenopausal atrophic urethritis
- Psychiatric causes (especially depression, delirium/confused state)
- Excessive urinary output (in conditions like hyperglycemia, hypercalcemia, CHF)
- Stool impaction
- Impaired mobility
General risk factors

DIAPPERS: Delirium/confusion, Infection, Atrophic urethritis/vaginitis, Pharmaceutical, Psychiatric causes (especially depression), Excessive urinary output (hyperglycemia, hypercalcemia, CHF), Restricted mobility, Stool impaction.

Overview

Overview of urinary incontinence
Type of incontinence	Pathophysiological mechanism	Key features ^[3]	Treatment ^[4]
Stress incontinence	Urethral hypermobility in women (bladder outlet incompetence) secondary to: Poor pelvic support caused by pelvic postmenopausal estrogen loss Connective tissue disorders Childbirth (i.e., damage of the pelvic floor muscle levator ani and/or the S2–S4 nerve roots) Intrinsic sphincter deficiency, caused by: Aging Obesity Pelvic trauma Prostate surgery (in men) Increase in intra-abdominal pressure (e.g., from laughing, sneezing, coughing, exercising) → ↑ pressure within the bladder → bladder pressure > urethral sphincter resistance to urinary flow	Positive bladder stress test: urinary leakage on activities that increase intra-abdominal pressure (e.g., coughing, Valsalva maneuver)	General principles of treatment of urinary incontinence Surgery (see “Treatment” in “Stress incontinence”)
Urge incontinence ^[5]	Inflammatory conditions (e.g., UTI) or neurogenic disorders → sphincter dysfunction, detrusor overactivity, or overactive bladder → autonomous contractions of the detrusor muscle and premature initiation of a normal micturition reflex	Strong, sudden sense of urgency, followed by involuntary leakage	General principles of treatment of urinary incontinence Anticholinergic medication (e.g., oxybutynin) Sympathomimetics: mirabegron Surgery (see “Treatment” in “Urge incontinence”)
Mixed incontinence	Combination of mechanisms of stress incontinence and urge incontinence	May have any of the clinical features above	General principles of treatment of urinary incontinence Anticholinergics to treat aspects of urge incontinence ^[6]
Total incontinence	Complete loss of sphincter function (due to previous surgery, nerve damage, metastasis) or abnormal anatomy (fistula between urinary tract and skin)	Urinary leakage occurs at all times, with no associated preceding symptoms or specific trigger activity.	General principles of treatment of urinary incontinence Usually requires surgery
Overflow incontinence (overflow bladder)	Impaired (weak) detrusor contractility due to: ^[7] Neurogenic bladder in multiple sclerosis Neuropathy and polyuria in diabetes mellitus Spinal cord injuries Medication side effects Bladder outlet obstruction (e.g., BPH) Both mechanisms can lead to incomplete bladder emptying → bladder overfilling → chronically distended bladder with ↑ bladder pressure → dribbling of urine (leak) when intravesical pressure > outlet resistance	Frequent, involuntary intermittent/continuous dribbling of urine in the absence of an urge to urinate Occurs only when the bladder is full Often occurs with changes in position Postvoid residual urine volume (seen on ultrasound or with catherization)	Acute settings: intermittent catheterization Timed voiding for day to day management Treatment of underlying condition (see also “Treatment” in “Urinary retention”) α-Blockers for BPH Antibiotics for UTI
Further causes of urinary incontinence	Commonly seen in multiple sclerosis or spinal cord injury ^[8] Detrusor sphincter dyssynergia → simultaneous contractions of the detrusor muscle and involuntary activation of the urethral sphincter → blockage of bladder outlet → small amounts of urine are pressed through the contracted sphincter muscle → high intravesical pressure along with inappropriate contraction of the urethral sphincter	Voiding and/or storage dysfunction, intermittent voiding, urinary retention Irregular, small volume incontinence without an associated urge to void (sometimes referred to as reflex incontinence)	General principles of treatment of urinary incontinence Injection of botulinum toxin into the detrusor muscle Transurethral resection of external urinary sphincter (TURS) Alpha-blockers and/or anticholinergics Urethral stent placement Endoscopic sphincterotomy ^[9]
Enuresis risoria ^[10]	Unknown; not related to stress or detrusor weakness	Affects children Involuntary complete voiding triggered by giggling or laughing Voiding behavior is otherwise normal (not a feature of enuresis).	General principles of treatment of urinary incontinence Reassurance Oxybutynin (second-line)

Neural control of micturition: parasympathetic nervous system → S2–S4 ventral root → inferior hypogastric plexus → contraction of the detrusor muscle → voluntary relaxation of the external urethral sphincter muscle via the pudendal nerve → micturition

Urinary incontinence Urinary bladder (male) Urinary bladder (female)

Diagnostics

Basic diagnostic testing

Detailed medical history (including medication)
Voiding diary: to assess the frequency and volume of micturition
Neurological, vaginal, and rectal examination: to detect local sites of infection (e.g., abscesses, sebaceous cysts), anomalies of local anatomy, neurological deficits, and rectal sphincter flaccidity
Laboratory tests
- Urine dipsticks and urine culture to exclude urinary tract infections
- Creatinine and blood urea nitrogen (BUN) to assess kidney function
Sonography
- Quantification of residual urine after micturition
- Renal ultrasound
Quantification of leaked urine: pad test

Additional diagnostic testing

Micturating cystourethrogram (MCU): to detect morphological abnormalities
Urodynamic examination: to measure bladder pressure and urethral closure pressure ^[11]
Cystoscopy: to rule out tumors and vesicorectal or vesicovaginal fistulae
MRI: to identify pelvic floor defects

See also “Diagnostics” in “Stress incontinence” and “Urge incontinence” articles for more information.

Treatment

General principles of treatment of urinary incontinence ^[4]^[5]

Lifestyle modifications
- Weight loss
- Dietary changes (e.g., decrease consumption of alcohol, caffeine, carbonated drinks)
- Smoking cessation
- Modification of other contributing factors (e.g., drugs)
Behavioral therapies and exercises
- Bladder training (e.g., timed voiding, relaxation/distraction techniques)
- Kegel exercises: an exercise targeting the pelvic floor in order to strengthen muscles that control urinary flow and bowel movements
- Biofeedback
- Vaginal-weighted cones
Physical measures to prevent leakage
- Vaginal pessary (a device inserted into the vagina in order to provide more support for pelvic organs) or penile compression devices
- Absorbent products
- Catheterization
- Urethral occlusion
Management of reversible causes (e.g., constipation)
Topical vaginal estrogen (in postmenopausal patients with vaginal atrophy)

Medical treatment

Autonomic drugs used to treat bladder incontinence
Drug group	Example drugs	Mechanism of action	Indication
Muscarinic antagonists	Oxybutynin	Blocks M3 receptor → detrusor muscle relaxation	Detrusor overactivity Urgency incontinence
Muscarinic agonists	Bethanechol	Stimulates M3 receptor → detrusor muscle contraction → emptying of the urinary bladder	Urinary retention
Sympathomimetics	Mirabegron	Stimulates β3 receptor → detrusor muscle relaxation → increased bladder capacity	Urgency incontinence
Alpha-1 antagonists	Tamsulosin	Blocks α1 receptor → relaxation of smooth muscles of bladder, neck, and prostate → reduced obstruction of urinary outflow	Benign prostatic hyperplasia

Other treatment options depend on the form of urinary incontinence; see the “Overview” section above as well as “Stress incontinence” and “Urge incontinence” articles.

Mechanism of action of medications used in micturition problems

Complications

General: depression, psychosocial distress
From prolonged contact with urine: dermatitis, skin infections, and sores
Urinary tract: : increased risk of urinary tract infections

We list the most important complications. The selection is not exhaustive.

References

Nitti VW. The prevalence of urinary incontinence. Rev Urol. 2001; 3 (Suppl 1): p.S2-6.
Gorina Y, Schappert S, Bercovitz A, et al. Prevalence of Incontinence Among Older Americans. Vital Health Stat. 2014; 3 (36).
Flesh G. Urodynamic Evaluation of Women with Incontinence. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/urodynamic-evaluation-of-women-with-incontinence.Last updated: March 7, 2016. Accessed: January 5, 2018.
Lukacz ES, Santiago-Lastra Y, Albo ME, Brubaker L. Urinary incontinence in women. JAMA. 2017; 318 (16): p.1592. doi: 10.1001/jama.2017.12137 . | Open in Read by QxMD
Lukacz ES. Treatment of Urinary Incontinence in Women. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/treatment-of-urinary-incontinence-in-women.Last updated: November 9, 2017. Accessed: December 13, 2017.
Lukacz ES. Evaluation of Women with Urinary Incontinence. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/evaluation-of-women-with-urinary-incontinence.Last updated: November 13, 2017. Accessed: December 13, 2017.
Welk B, Baverstock RJ. The management of mixed urinary incontinence in women. Canadian Urological Association Journal. 2017; 11 (6S2): p.121. doi: 10.5489/cuaj.4584 . | Open in Read by QxMD
Lobo RA. Treatment of the Postmenopausal Woman. Academic Press ; 2007
Kalsi V, Fowler CJ. Therapy insight: bladder dysfunction associated with multiple sclerosis. Nat Clin Pract Urol. 2005; 2 (10): p.492-501. doi: 10.1038/ncpuro0323 . | Open in Read by QxMD
Stoffel JT. Detrusor sphincter dyssynergia: a review of physiology, diagnosis, and treatment strategies.. Translational andrology and urology. 2016; 5 (1): p.127-35. doi: 10.3978/j.issn.2223-4683.2016.01.08 . | Open in Read by QxMD
Fernandes L, Martin D, Hum S. A case of the giggles: Diagnosis and management of giggle incontinence.. Can Fam Physician. 2018; 64 (6): p.445-447.

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