Urine volume; 24-hour Urine collection
A urine 24-hour volume tests the amount of urine produced in a day.
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.
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.
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 mellitus
- 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.
by Arthur A. Poghosian, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.