24-hour Urine Test
A 24-hour urine test measures the amount of urine a person produces in one day. It may be done with other tests to measure the excretion of certain substances into urine over a 24-hour period.
Who is a candidate for the test?
A 24-hour urine test may be ordered when a person has developed disorders in urine production. It provides information about the function of the kidneys.
How is the test performed?
This test is simple and can be done at home. The healthcare professional may give specific instructions on how to collect the sample. In general, this is the recommended schedule:
Day 1: The person urinates when he or she gets up. A sample is not collected at that time. For the rest of the day, however, the person uses a special container to collect all urine produced for the next 24 hours.
Day 2: Upon arising, the person urinates into the container. He or she then covers it and refrigerates it until delivering it to the healthcare professional.
What is involved in preparation for the test?
The person will be given a special container and instructions for urine storage.
What do the test results mean?
When a person has a normal intake of fluid, he or she produces a volume of urine ranging from 800 to 2000 milliliters per day (mL/day). A low urine volume may indicate dehydration, inadequate fluid intake, or kidney disease.
A high urine volume may indicate diabetes insipidus, a condition that interferes with normal excretion of urine. It may also indicate diabetes mellitus, high fluid intake, kidney disease, or use of diuretic medicines.