A post-void residual volume greater than 200 mL suggests which type of incontinence?

• A. Urge incontinence
• B. Overflow incontinence
• C. Functional incontinence
• D. Mixed incontinence

Answer: (B)

Post-void residual volume shows how much urine remains after voiding. A value over 200 mL means the bladder isn’t emptying fully, which allows urine to leak as the bladder overfills—this is characteristic of overflow incontinence. Overflow occurs when there is inadequate detrusor contraction or an outlet obstruction, so urine gradually overfills the bladder and leaks. In contrast, urge incontinence stems from involuntary detrusor contractions during filling, not from a high residual, and functional incontinence is due to problems getting to the toilet rather than bladder emptying. Mixed incontinence would involve multiple mechanisms, but the elevated residual volume specifically points to overflow.