What is the most common type of urinary incontinence in women and its primary mechanism?

• A. Stress urinary incontinence due to urethral hypermobility or intrinsic sphincter deficiency when intra-abdominal pressure rises.
• B. Urge urinary incontinence caused by detrusor overactivity during bladder filling.
• C. Overflow urinary incontinence due to incomplete bladder emptying.
• D. Functional incontinence resulting from cognitive or physical barriers to toileting.

Answer: (A)

Stress urinary incontinence is the most common type of urinary leakage in women, and it happens when leakage occurs with activities that raise intra-abdominal pressure, like coughing, sneezing, laughing, or lifting.

The key mechanism is a loss of urethral closure support. If the pelvic floor and surrounding tissues that keep the urethra in place are weakened, the urethra can become hypermobile or the sphincter itself can be deficient. When pressure increases, the open, inadequately supported urethra cannot stay closed, so urine leaks.

This contrasts with urge incontinence, where leakage comes from involuntary detrusor contractions during bladder filling; overflow incontinence, from incomplete bladder emptying; and functional incontinence, from cognitive or physical barriers to toileting.