Urinary Incontinence: Classification

UI Basics - Leaky Pipes 101

• Definition: Any involuntary leakage of urine.
• A common & distressing symptom; significantly impacts quality of life (QoL).
• Risk factors: ↑ Age, parity, obesity, menopause, previous pelvic surgery.
• Main classifications:
  • Stress UI (SUI)
  • Urgency UI (UUI) / Overactive Bladder (OAB)
  • Mixed UI (MUI)
  • Overflow UI
  • Functional UI

⭐ Urinary incontinence (UI) is the complaint of any involuntary leakage of urine. It is NOT a normal part of aging, though its prevalence increases with age.

Stress UI - Cough & Sneeze Leaks

• Involuntary urine loss on effort or exertion (e.g., coughing, sneezing, laughing, lifting).
• Primary Mechanisms:
  • Urethral Hypermobility: Weak pelvic floor support leads to downward/rotational descent of urethra & bladder neck.
  • Intrinsic Sphincter Deficiency (ISD): Weakness of the urethral sphincter's closing mechanism.
• Common Risk Factors:
  • Pregnancy, childbirth (especially vaginal).
  • Obesity, chronic cough, constipation.
  • Menopause (↓ estrogen).
  • Previous pelvic surgery.
• Diagnostic Clues:
  • History of leakage with physical stress.
  • Positive cough stress test (observed leakage).

⭐ In Stress Urinary Incontinence (SUI), a positive Q-tip test (angle > 30 degrees from horizontal with Valsalva) suggests urethral hypermobility.

Urgency UI/OAB - Gotta Go NOW!

• UUI: Involuntary urine leakage with/preceded by urgency.
• OAB Syndrome: Urgency (key), often with frequency (>8/24h) & nocturia (>1/night), +/- UUI.
• Pathophysiology: Detrusor Overactivity (DO) - involuntary bladder contractions during filling.
  • Idiopathic (most common) or Neurogenic.
• Triggers: 📌 Key-in-lock phenomenon, running water, cold.

⭐ Detrusor overactivity is the most common urodynamic finding in patients with Urgency Urinary Incontinence (UUI); Overactive Bladder (OAB) is a syndrome of urgency, usually with frequency and nocturia, +/- UUI.

• Management:
  • Behavioral (bladder training)
  • Meds (antimuscarinics, β3-agonists)
  • Advanced (Botox, neuromodulation)

Mixed & Overflow UI - Combo & The Dam

• Mixed UI:
  • Combination of Stress UI (SUI) and Urgency UI (UUI).
  • Patient experiences symptoms of both involuntary leakage on effort/exertion AND urgency with leakage.
  • Common, especially in older women.
• Overflow UI: 📌 (Mnemonic: "The Dam is Full")
  • Involuntary urine loss when bladder pressure exceeds urethral pressure due to bladder overdistension, without detrusor contraction.
  • Causes:
    • Bladder Outlet Obstruction (BOO): e.g., BPH, urethral stricture, severe pelvic organ prolapse.
    • Detrusor Underactivity: e.g., neurogenic (diabetes, MS), myogenic, medications (anticholinergics).
  • Symptoms: Dribbling, weak stream, hesitancy, nocturia, feeling of incomplete emptying.

  ⭐ A post-void residual (PVR) urine volume > 200 mL is often indicative of overflow incontinence or significant bladder emptying dysfunction.

Functional & Transient UI - Odd Jobs & Quick Fixes

• Functional UI: Due to cognitive/physical impairments (e.g., dementia, immobility) preventing toilet use.
• Transient UI: Temporary, often reversible causes.
  • 📌 Key: DIAPPERS mnemonic.

⭐ The 'DIAPPERS' mnemonic (Delirium, Infection, Atrophic urethritis/vaginitis, Pharmaceuticals, Psychological, Excess urine output, Restricted mobility, Stool impaction) is crucial for identifying reversible causes of transient incontinence.

High‑Yield Points - ⚡ Biggest Takeaways

• SUI: Leakage on effort (cough, sneeze); due to urethral hypermobility or Intrinsic Sphincter Deficiency (ISD).
• UUI: Leakage with urgency; due to detrusor overactivity.
• MUI: Combination of SUI and UUI symptoms.
• Overflow Incontinence: Dribbling from overfull bladder; due to detrusor underactivity or bladder outlet obstruction; ↑ PVR.
• Continuous Incontinence: Constant leakage; suspect urinary fistula (e.g., Vesicovaginal Fistula - VVF).
• Urodynamics (UDS): Key for complex cases or before incontinence surgery.