Urinary Incontinence in Women

Definition

Urinary incontinence (UI) in women is the involuntary leakage of urine that represents a social or hygienic problem, classified into stress, urge, mixed, overflow, and functional types based on underlying pathophysiology.

Epidemiology

• Affects up to 30–40% of adult women; prevalence increases with age and parity
• More common in postmenopausal women due to estrogen deficiency
• Stress incontinence is the most common type in younger and middle-aged women
• Urge incontinence and mixed types are more common in older women
• Risk factors include multiparity, obesity, pelvic surgery, and chronic cough

Etiology

• Stress incontinence: urethral hypermobility or intrinsic sphincter deficiency due to pelvic floor weakness
• Urge incontinence: detrusor overactivity (idiopathic or neurogenic)
• Overflow incontinence: bladder outlet obstruction or detrusor underactivity
• Functional incontinence: inability to reach toilet due to physical or cognitive impairment
• Risk factors: childbirth, menopause, pelvic surgery, obesity, chronic constipation, smoking

Pathophysiology

• Stress UI: increased intra-abdominal pressure exceeds urethral closure pressure due to weakened pelvic floor
• Urge UI: involuntary detrusor contractions during bladder filling
• Mixed UI: combination of stress and urge mechanisms
• Overflow UI: chronic urinary retention leading to leakage from overdistended bladder
• Pelvic floor damage from childbirth or estrogen deficiency contributes to decreased urethral support