Healthcare providers have always relied on the analysis of urine collections in order to detect and treat many disease processes. Twenty-four hour urine collections are often employed to estimate the production rates of various hormones. The accuracy of test results depend on compliance of the collection technique prescribed. These instructions are provided as a guide to ensure that your 24-hour urine collection is obtained in a manner that will permit reliable test results.
You should collect every drop of your urine produced during a 24-hour period. You should begin the collection in the morning or at a time specified by your physician. At that time, pass your urine and flush it down the toilet noting the exact time. These measures permit you to start with an empty bladder and an empty collection container. Thereafter, collect every single drop of urine during the day and following night. The very next morning, 24-hours after the start time you should empty your bladder entirely. This last step, will complete the collection. There should be no more than a 5 minute or 10 minute variation between the start time and stop time. If you find that you must urinate an hour or so before your completion time, that’s fine. You should then drink a full glass of water so you can urinate again at the correct time to end the collection.
Urine samples should be collected in a large cup or other container then poured into the container. Do not try to urinate directly into the bottle as this could result in an inaccurate volume. Also, collect urine sample before a bowel movement to avoid losing volume.
Some patients are asked to collect more than one 24-hour collection. If this is the case, you should complete the collection as instructed. To begin subsequent collections you do not need to discard any urine between samples. Simply change bottles at the start and stop times after adding the last sample required to complete the previous collection.
The bottles of some containers contain a weak acid as a preservative. Do not discard the acid. If you accidentally get acid or urine from the bottle on your skin or clothing, rinse the affected area immediately with cold water. Twenty-four hour urine collection bottles must be refrigerated. This is best accomplished by using an ice chest, cooler or the refrigerator.
If you forget to collect all of the urine or perform the test improperly, discard the specimen and begin the test the next day. If the bottle contained an acid preservative, another one must be obtained from a laboratory or physician's office. Otherwise, you may use the bottle after rinsing it with distilled water.
Finally, please remember to call your physician or nurse if you have any questions about the proper collection of a 24- hour urine sample.