Cystometry is a diagnostic test used to measure the pressure and volume of urine inside the bladder during bladder filling and emptying. This test is often performed to evaluate the bladder’s function and diagnose urinary disorders such as urinary incontinence, urinary retention, and overactive bladder.

During cystometry, a catheter is inserted into the bladder through the urethra, and another catheter is inserted into the rectum to measure intra-abdominal pressure. The bladder is then filled with sterile water or saline at a controlled rate while the pressure inside the bladder and urine volume is measured. The patient is also asked to report any sensations of fullness or discomfort during bladder filling and to urinate when instructed to do so to measure the pressure and volume of urine during bladder emptying.

The results of cystometry can help diagnose conditions such as detrusor overactivity (involuntary contractions of the bladder muscle), stress urinary incontinence (leakage of urine during physical activity or coughing), and bladder outlet obstruction (blockage of urine flow from the bladder). The test is usually performed in a hospital or clinic setting and may take about 30 to 60 minutes to complete.