disorders of urination
kidney and urinary tract disorders
Urinary Retention
Measurement of urine remaining in the bladder after urination If a person is unable to pass any urine, the diagnosis is clear. In other cases, doctors try to see how much urine remains in the bladder after the person has urinated as much as they can. Immediately after the person urinates, doctors either insert a catheter into the bladder to see how much urine comes out or do ultrasonography of the bladder to measure the amount of urine present. The amount of urine left after urinating is called postvoid residual volume. If this volume is more than about half a cup (slightly more in older adults), urinary retention is diagnosed. Doctors do a physical examination, usually including a rectal examination. In men, the rectal examination can indicate whether the prostate is enlarged. In men and women, the rectal examination helps identify a fecal impaction. Doctors may take a sample of urine to test for infection. Blood tests and imaging tests may be needed to determine the cause of urinary retention. 