| Subject | Contents |
| Definition | This test measures the amount of uric acid in urine. |
| Alternative Names | Uricosuria |
| 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 upon arising in the morning. Collect all subsequent urine (in a special container) for the next 24 hours. On day 2, urinate into the container in the morning upon arising. 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. Infant: 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 your 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. Place a diaper over the infant (bag and all). The infant should be checked frequently and the bag changed after the infant has urinated into the bag. For active infants, this procedure may take a couple of attempts -- lively infants can displace the bag, causing an inability to obtain the specimen. 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. |
| How to prepare for the test | The health care provider may advise you to discontinue drugs that can affect the test (see "special considerations"). If the collection is being taken from an infant, a couple of extra collection bags may be necessary. |
| How the test will feel | The test involves only normal urination, and there is no discomfort. |
| Why the test is performed | The most common reason for measuring uric acid levels is in the evaluation, diagnosis, and treatment of kidney stones. Patients with gout may also be evaluated using this test, since a significant number of patients with gout develop uric acid kidney stones. Uric acid is the end-product of purine catabolism. Purines (such as adenine and guanine) are components of nucleotides, which are the building blocks of the nucleic acids (such as RNA and DNA). |
| Normal Values | Normal values range from 250 to 750 mg/24 hours. Note: mg/24 hr = milligrams per 24 hours |
| What abnormal results mean | Abnormal results are indicated as follows: Greater-than-normal urinary uric acid levels may indicate: Metastatic cancers Myelo and lymphoproliferative disorders High purine diet Gout RhabdomyolysisLesch-Nyhan syndrome Fanconi syndrome Lower-than-normal urinary uric acid levels may indicate:Chronic alcohol ingestionChronic glomerulonephritisLead poisoning |
| What the risks are | |
| Special considerations | Interfering factors for this test include: High levels of Vitamin CX-ray contrast agents Drugs that can interfere with test results include: alcohol, anti-inflammatory drugs (such as NSAIDs), salicylates, thiazide diuretics, allopurinol, and probenecid. |
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