Urine 24-hour volume

Definition

The urine 24-hour volume test measures the amount of urine produced in a day. The amounts of creatinine, protein, and other chemicals released into the urine during this period are usually tested as well.

Alternative Names

Urine volume; 24-hour urine collection; Urine protein - 24 hour

How the Test is Performed

For this test, you must urinate into a special bag or container every time you use the toilet for a 24-hour period.

• On day 1, urinate into the toilet when you get up in the morning.
• Afterward, collect all urine in a special container for the next 24 hours.
• On day 2, urinate into the container when you get up in the morning.
• Cap the container. Keep it in the refrigerator or a cool place during the collection period.
• Label the container with your name, the date, the time of completion, and return it as instructed.

For an infant:

Thoroughly wash the area around the urethra (the hole where urine flows out). Open a urine collection bag (a plastic bag with an adhesive paper on one end).

• For males, place the entire penis in the bag and attach the adhesive to the skin.
• For females, place the bag over the two folds of skin on either side of the vagina (labia). Put a diaper on the baby (over the bag).

Check the infant often, and change the bag after the infant has urinated. Empty the urine from the bag into the container provided by your health care provider.

An active infant can cause the bag to move. It may take more than one try to collect the sample.

When finished, label the container and return it as instructed.

How to Prepare for the Test

Certain drugs can also affect the test results. Your provider may tell you to stop taking certain medicines before the test. Never stop taking medicine without first talking to your provider.

The following may also affect test results:

• Dehydration
• Dye (contrast media) if you have a radiology scan within 3 days before the urine test
• Emotional stress
• Fluid from the vagina that gets into the urine
• Strenuous exercise
• Urinary tract infection

How the Test will Feel

The test involves only normal urination and there is no discomfort.

Why the Test is Performed

You may have this test if there are signs of damage to your kidney function on blood, urine, or imaging tests.

Urine volume is normally measured as part of a test that measures the amount of a substances passed in your urine in a day, such as:

• Creatinine
• Sodium
• Potassium
• Urea nitrogen
• Protein

This test may also be done if you have polyuria (abnormally large volumes of urine), such as is seen in people with diabetes insipidus.

Normal Results

The normal range for 24-hour urine volume is 800 to 2,000 milliliters per day (with a normal fluid intake of about 2 liters per day).

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Disorders that cause reduced urine volume include dehydration, not enough fluid intake, or some types of chronic kidney disease.

Some of the conditions that cause increased urine volume include:

• Diabetes insipidus - renal
• Diabetes insipidus - central
• Diabetes
• High fluid intake
• Some forms of kidney disease
• Use of diuretic medicines

References

Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 106.

Verbalis JG. Disorders of water balance. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 15.