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Uroflowmetry

Definition

Uroflowmetry is a test that measures the volume of urine released from the body, the speed with which it is released, and how long the release takes.

Alternative Names

Uroflow

How the test is performed

You will urinate in a special urinal or toilet with a machine that has a measuring device.

You will be asked to begin urinating after the machine has started. When you finish, the machine will create a report for your health care provider.

How to prepare for the test

Your health care provider may ask you to temporarily stop taking medications that can affect the test results.

Uroflowmetry is best done when you have a full bladder. Do not urinate for 2 hours before the test. Drink extra fluids so you will have plenty of urine for the test.

Do not place any toilet tissue in the test machine.

How the test will feel

The test involves normal urination, so you should not experience any discomfort.

Why the test is performed

This test is useful in evaluating the function of the urinary tract. Usually, a patient having this test will report urination that is too slow.

Normal Values

Normal values vary depending on age and sex. In men, urine flow declines with age. Women have less change with age:

  • Ages 4 - 7
  • Ages 8 - 13
  • Ages 14 - 45
  • Ages 46 - 65
  • Ages 66 - 80

What abnormal results mean

Results are compared with your symptoms and physical exam. A result that may need treatment in one patient may not need treatment in another patient.

Several circular muscles normally regulate urine flow. If any of these muscles becomes weak or stops working, you may have an increase in urine flow or urinary incontinence .

If there is a bladder outlet obstruction or if the bladder muscle is weak, you may have a decrease in urine flow. The amount of urine that remains in your bladder after urinating can be measured with ultrasound.

Your health care provider should explain and discuss any abnormal results with you.

What the risks are

There are no risks with this test.

Special considerations

References

Nitti VW. Urodynamic and videourodynamic evaluation of the lower urinary tract. In: Wein AJ, ed. . 10th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 66.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.