24-Hour Collection of Urine Samples
24-Hour Urine Tests Check for Urinary, Kidney and Other Disorders
Urine samples collected over a 24-hour period are used for a variety of tests, such as those designed to screen and diagnose metabolic or kidney disorders. Your doctor may order a test to determine the cause of discolored urine, a decreased amount of urine or other symptoms.
Preparation and Procedure
Your doctor will give you specific instructions to follow to prepare for the particular test ordered. For example, some urine tests, including those for metanephrine, vanillylmandelic acid (VMA) and hydroxyindoleacetic acid (5HIAA), require that you observe certain dietary restrictions.
Before beginning your 24-hour urine collection, you will need to pick up a special container from the lab.
- Pick a start time, such as when you wake up in the morning. Void into the toilet and flush. Note the time and date on the lab container as your start time.
- Collect all urine voided over the next 24 hours in the lab container and keep in a cool place such as a refrigerator or cooler with ice. Additional containers are available if needed.
- Caution: do not urinate directly into the lab container. It may contain an amount of concentrated acid that could splash and burn you. Instead, void into another clean container, then carefully pour all the contents into the lab container.
- At the end of the 24-hour period, empty your bladder one last time, add this sample to the lab container and note the time and date on the container as your end time.
- Deliver the container with the entire specimen to the lab as soon as possible. If you expect a delay, refrigerate the specimen to retard growth of bacteria that could affect test results.
For most tests, your time at the lab will be limited to the amount of time it takes to sign in, register with admitting and leave your specimen. If your doctor has ordered a creatinine test, however, you will also need to have your blood drawn.
Results from your urine test are typically sent to your doctor within days; be assured, however, that any critical results are communicated immediately. Your doctor will discuss the results with you once he or she has reviewed them.
Doctor's Order Required
Michigan law requires that a valid order signed by an authorized person be presented before any laboratory test or procedure can be conducted. Authorized persons are defined as physicians, physician assistants, or nurse practitioners. These professionals are legally responsible for interpreting the results of tests based on their knowledge of the individual patient.