• Clinical science

Urinary incontinence

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.

Epidemiology

Epidemiological data refers to the US, unless otherwise specified.

Etiology

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
  • Positive bladder stress test: urinary leakage on activities that increase intra-abdominal pressure (e.g., coughing, Valsalva maneuver)
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
Mixed incontinence
  • May have any of the clinical features above
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.
Overflow incontinence (overflow bladder)
  • 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”)
Further causes of urinary incontinence
  • 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)
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).

Neural control of micturition: parasympathetic nervous systemS2–S4 ventral root → inferior hypogastric plexus → contraction of the detrusor muscle → voluntary relaxation of the external urethral sphincter muscle via the pudendal nerve micturition

Diagnostics

Basic diagnostic testing

Additional diagnostic testing

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

Treatment

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

  • 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
Muscarinic agonists
Sympathomimetics
Alpha-1 antagonists

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

Complications

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