Urine 24-hour volume

Definition

The urine 24-hour volume test measures the amount of urine produced in a day.

Alternative Names

How the test is performed

A 24-hour urine sample is needed. The health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test.

• On day 1, urinate into the toilet when you get up in the morning.
• Afterwards, 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 INFANTS

Thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Diaper as usual over the secured bag.

This procedure may take a couple of attempts -- lively infants can displace the bag, causing the specimen to be absorbed by the diaper. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. The urine is drained into the container for transport to the laboratory.

Deliver it to the laboratory or your health care provider as soon as possible upon completion. The laboratory will measure the volume of urine in the specimen.

How to prepare for the test

No special preparation is necessary for this test, but if the collection is being taken from an infant, a couple of extra collection bags may be necessary.

Drink a normal volume of fluids, and consume a normal diet.

How the test will feel

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

Why the test is performed

Urine volume is normally measured as a part of the creatinine clearance test, or any test that measures the amount of a substance eliminated in a day (for example, protein, aldosterone, sodium, potassium, urea nitrogen). It is also measured in patients with polyuria (abnormally large volumes of urine), such as diabetes insipidus.

See also:

• Sodium - urine
• Potassium - urine
• Urea nitrogen - urine

Normal Values

800 to 2000 ml/day (with a normal fluid intake of about 2 L/day)

Normal value ranges may vary slightly among different laboratories.

Note: ml/day = milliliter per day; L/day = liters per day

What abnormal results mean

Disorders that cause reduced urine volume include dehydration, inadequate fluid intake, or renal insufficiency or failure.

Some of the conditions that cause increased urine volume include:

• Diabetes insipidus - renal
• Diabetes insipidus - central
• Diabetes
• High fluid intake
• Some forms of kidney failure
• End-stage renal disease
• Use of diuretic medications

What the risks are

There are no risks, except for the chance of inaccurate results if all of the urine is not collected during the 24-hour period.

Special considerations

Not applicable.