Which statement about urodynamics is true?

• A. It evaluates upper urinary tract function
• B. It evaluates lower urinary tract function
• C. It replaces imaging entirely
• D. It is not used in adults

Answer: (B)

Urodynamics focuses on how the lower urinary tract stores and releases urine. It measures pressures, volumes, and flow during filling and voiding to understand storage and voiding function. This includes assessing bladder capacity, compliance, detrusor activity (such as overactivity or underactivity), and how the bladder and urethral sphincter coordinate to empty. The findings help distinguish whether symptoms come from an overactive bladder, poor bladder compliance, bladder outlet obstruction, or detrusor underactivity, and they’re especially helpful in complex or neurogenic cases.

It does not evaluate the upper urinary tract (kidneys and ureters); imaging and renal tests are used for that. Imaging provides anatomy and upper tract status, while urodynamics gives the functional picture of the lower tract. It’s widely used in adults as well as children, not only in younger patients.