What is the role of post-void residual measurement in evaluating incontinence?

• A. To assess bladder emptying; elevated PVR suggests overflow incontinence or detrusor underactivity.
• B. To diagnose kidney stones.
• C. To assess urinary frequency.
• D. To test sphincter strength.

Answer: (A)

Post-void residual measurement is about how much urine remains in the bladder after a person tries to void. This tells you how well the bladder is emptying. If the residual urine is high, it points to poor emptying, which fits with overflow incontinence or detrusor underactivity (or possible outlet obstruction). In contrast, many forms of incontinence such as urge or stress incontinence involve leakage without a problematic retention pattern, so the residual is often normal or low. So measuring PVR helps distinguish retention-related causes from leakage due to other mechanisms and guides management—recognizing when there may be detrusor weakness, obstruction, or neurogenic issues, and influencing choices about further testing or treatment. It isn’t used to diagnose kidney stones, to assess urinary frequency by itself, or to test sphincter strength.