Urinary incontinence

Last updated: September 14, 2023

Summary

Urinary incontinence (UI) is a common condition characterized by involuntary leakage of urine. Causes and presentations are variable. Stress incontinence, urge incontinence, and mixed incontinence are the most common types. UI is more common in older individuals, and approximately twice as common in women than in men. The diagnosis can often be made based on a detailed medical history, a voiding diary, physical examination, and basic testing including urinalysis and measurement of postvoid residual volume (PVR). Advanced diagnostic studies may be required for patients with red flags in urinary incontinence or incontinence refractory to treatment. Initial management involves conservative measures (e.g., management of comorbidities, pelvic floor exercises, bladder training) and provision of continence products; further treatment is based on the underlying mechanism and may involve pharmacotherapy or surgery. If left untreated, UI can have a severely detrimental effect on patients' psychosocial well-being, mobility, and independence, and can increase the risk of infection.

For the management of stress incontinence and urge incontinence, see also the respective articles.

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
Transient causes of urinary incontinence
- 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

To remember the reversible causes of acute urinary incontinence, think DIAPPERS: Delirium/confusion, Infection, Atrophic urethritis/vaginitis, Pharmaceutical, Psychiatric causes (especially depression), Excessive urinary output (hyperglycemia, hypercalcemia, CHF), Restricted mobility, Stool impaction.

Overview

Types of urinary incontinence

Overview of urinary incontinence ^[3]^[4]^[5]
	Underlying mechanism	Clinical features	Treatment
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 intraabdominal 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 during activities that increase intraabdominal pressure (e.g., coughing, Valsalva maneuver)	Trial of conservative management of UI for 6–8 weeks ^[5] In refractory or severe incontinence, refer to urology for: ^[4] Minimally-invasive solutions, e.g., vaginal pessaries or urethral inserts Injection of periurethral bulking agents Surgical procedures (e.g., urethral slings or suspensions, artificial urinary sphincter) See “Treatment of stress incontinence” for additional information.
Urge incontinence ^[6]	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	Conservative management of UI First line: pharmacotherapy Anticholinergics (e.g., oxybutynin) Sympathomimetic (e.g., mirabegron) Second line: interventional procedures (e.g., sacral nerve stimulation, injection of botulinum toxin into the bladder wall) See “Treatment of urge incontinence” for additional information.
Mixed incontinence	Combination of mechanisms of stress incontinence and urge incontinence	May have any of the clinical features above	Conservative management of UI Treat the most bothersome symptom first, e.g., anticholinergics for urge incontinence. ^[3]^[7]^[8]
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.	Short-term management: pads and external catheters ^[9] Long-term management: usually surgical (e.g., fistula repair), in consultation with urology and/or urogynecology ^[3]
Overflow incontinence (overflow bladder) ^[10]	Impaired (weak) detrusor contractility due to: ^[11] Neurogenic bladder in multiple sclerosis Neuropathy and polyuria in diabetes mellitus Spinal cord injury Medication adverse 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)	Short-term management includes: Intermittent catheterization: for scheduled bladder emptying Alpha-1 antagonists: for outlet obstruction in men Muscarinic agonists: for detrusor underactivity ^[12] Long-term management includes treatment of the urinary obstruction, e.g.: Correction of pelvic organ prolapse Transurethral resection of the prostate Urethral dilation or urethroplasty See also “Treatment of urinary retention.”
Neurogenic bladder dysfunction ^[3]^[13]	Depending on the location of the lesion, can cause: Detrusor overactivity (spastic neurogenic bladder), e.g.: 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 Commonly seen in multiple sclerosis and spinal cord injury ^[14] Detrusor areflexia (flaccid neurogenic bladder)	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)	Initial management: usually conservative Patients with high PVR : intermittent catheterization with or without muscarinic antagonists Management of detrusor overactivity with minimal PVR Good cognitive function and/or mobility: Trial conservative management of UI and muscarinic antagonists. Poor cognitive function and/or mobility: Manage with continence products or an indwelling catheter. Further management depends on the subtype and includes: Minimally invasive interventions Surgical management ^[15]
Enuresis risoria ^[16]	Unknown; not related to stress or detrusor weakness	Affects children Involuntary complete voiding triggered by laughing Voiding behavior is otherwise normal (not a feature of enuresis).	Conservative management of UI 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

Stress incontinence is caused by urethral dysfunction, while urge incontinence is caused by bladder dysfunction. Mixed incontinence is a combination of both. ^[17]

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

Overview of pharmacotherapy

Autonomic drugs used to treat bladder incontinence ^[3]^[4]^[5]
Drug group	Indications	Mechanism of action
Muscarinic antagonists e.g., oxybutynin	Urge incontinence (detrusor overactivity)	Blocks M3 receptor → detrusor muscle relaxation
Sympathomimetics e.g., mirabegron	Urge incontinence (detrusor overactivity)	Stimulates β3 receptor → detrusor muscle relaxation → increased bladder capacity
Muscarinic agonists e.g., bethanechol ^[10]^[12]	Urinary retention	Stimulates M3 receptor → detrusor muscle contraction → emptying of the bladder
Alpha-1 antagonists e.g., tamsulosin	Outlet obstruction associated with BPH	Blocks α1 receptor → relaxation of smooth muscles in the bladder neck and prostate → reduced obstruction of urinary outflow

The use of muscarinic agonists may lead to urinary urgency, while the use of sympathomimetics or muscarinic antagonists may lead to urinary retention, especially if there is an untreated outlet obstruction. ^[3]

No pharmacological therapies are FDA-approved for stress incontinence; treatment is primarily conservative with surgery. ^[4]

Mechanism of action of medications used in micturition problems

Diagnostics

The following outlines a general approach for the workup of incontinence of unknown mechanism; if the mechanism is known, see “Diagnostics” in “Stress incontinence” and “Urge incontinence.”

Approach

All patients: Perform an initial evaluation for urinary incontinence.
- Screen for red flags in urinary incontinence.
- Take a thorough history and examine the lower abdomen and relevant systems.
- Perform a urinary stress test.
- Obtain initial diagnostic studies.
- Determine the type of incontinence.
Suspected upper urinary tract involvement : Obtain renal ultrasound and laboratory studies.
Red flags in urinary incontinence present or refractory incontinence: Referral to a specialist for further diagnostics.

Red flags in urinary incontinence ^[3]^[5]^[17]

Refer to urology or urogynecology for specialist workup if any of the following features are present:

Associated pain
Persistent hematuria or proteinuria
Elevated PVR
Symptoms suggestive of obstruction
Suspected fistula
Pelvic organ prolapse
Recurrent UTIs
Incontinence after radiation, radical pelvic surgery, or previous incontinence surgery

Initial evaluation for urinary incontinence ^[3]^[4]^[18]

Focused history

Chronicity: Determine whether the incontinence is acute or chronic.
- Acute: Screen for transient causes of urinary incontinence and reassess after they have been treated. ^[17]
- Chronic: Take a general history followed by a focused history.
General history
- Screen for relevant chronic and/or previous medical conditions and treatments.
  - Local causes: back, bowel, gynecologic, or bladder surgery; constipation; pelvic organ prolapse
  - Systemic conditions: congestive heart failure, chronic cough , neurological disease
- Assess for contributing dietary and lifestyle factors.
Focused history of incontinence
- If possible, use a validated incontinence questionnaire. ^[3]^[5]
- Inquire about symptoms that occur with voiding.
- Assess for barriers to voiding (e.g., limited mobility, which may delay patients reaching the bathroom).
- Ask patients to record fluid intake and micturition for 3–5 days using a voiding diary.

Physical examination ^[3]^[17]

Lower abdominal examination
- Evaluate for bladder distention and masses.
- Perform a urinary stress test. ^[5]
Digital rectal examination: Assess for fecal impaction, prostatomegaly, masses, and decreased anal sphincter tone.
Pelvic examination: Evaluate for pelvic organ prolapse, vaginal atrophy, masses, and vaginitis. ^[3]
Cardiovascular examination: Assess for signs of fluid overload (may worsen urge incontinence).
Neurological examination: Both spinal and cerebral pathologies can cause incontinence (see “Etiology”).
- Assess motor function of the lower extremities and sensation of the sacral dermatomes.
- Consider cognitive testing.

Perform a urinary stress test in all patients to distinguish between stress and urge incontinence.

Initial diagnostics

Urinalysis
- Positive urinary nitrites and/or leukocyte esterase: suggestive of a UTI; send urine culture.
- Isolated microhematuria: may be due to an enlarged prostate, pelvic prolapse, or urinary tract malignancy ^[19]
- Glucosuria: If present, screen for diabetes. ^[20]
Postvoid residual volume (PVR) ^[10]
- Indications ^[3]^[5]^[17]
  - Suspected overflow incontinence
  - Diagnostic uncertainty
  - Patients being considered for specialist referral
- Findings: Elevated PVR suggests either decreased bladder contractility or urethral obstruction. ^[4]^[17]

Differentiation between types of incontinence

Diagnostic overview of types of incontinence ^[17]
	Clinical history	Urinary stress test	Postvoid residual volume
Stress incontinence	Leakage with coughing, sneezing, and/or exercising	Leakage with coughing	< 50 mL
Urge incontinence	Symptoms of urinary urgency	May have delayed leakage ^[17]	< 50 mL
Overflow incontinence	No symptoms of urinary urgency or stress incontinence	No leakage	> 200 mL
Functional urinary incontinence	Patients may have: Mobility issues Symptoms of cognitive impairment	No leakage	Variable
Patients with features of both stress and urge incontinence have mixed incontinence.

Upper urinary tract studies ^[3]^[21]

Renal ultrasound
- Indications include:
  - Hematuria
  - Neurogenic incontinence
  - Elevated PVR
  - Comorbid renal disease
- Findings may show:
  - Hydronephrosis associated with overflow incontinence
  - Urinary tract pathology, e.g., malignancy
Creatinine and BUN: may be elevated in patients with overflow incontinence

Only perform upper urinary tract studies if the initial assessment indicates a possible renal pathology and/or renal impairment due to urinary retention and vesicoureteral reflux. ^[5]^[21]

Advanced studies ^[3]^[4]^[22]

Advanced studies are performed under specialist guidance for patients with red flags in urinary incontinence or incontinence refractory to initial management.

Micturating cystourethrogram: to detect vesicoureteral reflux and/or morphological abnormalities (e.g., diverticula, obstruction)
Urodynamic studies: to determine detrusor and sphincter function
Cystoscopy: to evaluate for tumors and vesicorectal and vesicovaginal fistulae
Ultrasound pelvis : for suspected pelvic floor dysfunction
MRI : to assess for pelvic floor defects, urinary tract anomalies, and masses
CT with IV contrast: for suspected anatomical abnormalities, e.g., urinary tract masses, bladder wall thickening

Management

Approach ^[3]

Identify and manage:
- Transient causes of UI, e.g., urinary tract infection, constipation
- Barriers to voiding
Initiate conservative management of UI for all patients.
Start specific management based on the subtype.
Refer patients with any of the following to urology for further management:
- Stress incontinence refractory to conservative therapy
- Red flags in urinary incontinence
- Neurogenic incontinence or total incontinence
Continence products (e.g., pads, external catheters) may be helpful as a temporary or permanent adjunct.

Assess the impact of incontinence symptoms on the patient's daily activities and discuss their treatment goals; use shared decision-making to individualize treatment plans.

Conservative management of urinary incontinence ^[6]^[8]

Management of comorbidities

Treatment of conditions such as chronic cough or DM may reduce symptom severity.
Review medication and, if possible, reduce the dose or discontinue contributing medications, e.g., diuretics.
Refer patients with limited mobility to physical therapy and occupational therapy.
Consider topical estrogen for postmenopausal women. ^[23]

Lifestyle recommendations

Management of obesity ^[4]
Smoking cessation
Limiting consumption of alcohol and caffeine (including carbonated drinks)
Appropriate fluid intake and timing throughout the day ^[5]

Pelvic floor physical therapy ^[24]

Exercises that target the pelvic floor to strengthen the muscles that control urinary flow and bowel movements
To increase efficacy, exercises may be supplemented with:
- Weighted vaginal cones
- Biofeedback

Bladder training

Scheduled voiding regimens and patient education are used to increase leak-free intervals. ^[4]
- Timed voiding: Intervals between voiding are sequentially increased until the goal of at least 3–4 hours is met.
- Relaxation and distraction techniques: used to suppress the urge to urinate.
Indications: urge incontinence, but also effective for stress and mixed incontinence

Type-specific management

Provide either alongside or after a trial of conservative management of UI.
- After a 6–8 week trial: stress incontinence ^[5]
- Alongside: all other forms of incontinence
For further information, see:
- Treatment of stress incontinence
- Treatment of urge incontinence
- Overview of UI (for management of mixed, total, neurogenic, or overflow incontinence)

Special patient groups