Uric acid - urine
The urine uric acid test measures the level of uric acid in urine.
Uric acid level can also be checked using a blood test.
How the Test is Performed
A 24-hour urine sample is needed. You will need to collect your urine over 24 hours. Your health care provider will tell you how to do this. Follow instructions exactly so that the results are accurate.
How to Prepare for the Test
Your health care provider may ask you to temporarily stop medicines that may affect the test results. Be sure to tell your provider about all the medicines you take. These include:
- Aspirin or aspirin-containing medicines
- Gout medicines
- Nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen)
- Water pills (diuretics)
Be aware that alcoholic drinks, vitamin C, and x-ray dye can also affect test results.
How the Test will Feel
The test involves only normal urination. There is no discomfort.
Why the Test is Performed
This test may be done to monitor people with gout, and to choose the best medicine to lower uric acid level in the blood.
Uric acid is a chemical created when the body breaks down substances called purines. Most uric acid dissolves in blood and travels to the kidneys, where it passes out in urine. If your body produces too much uric acid or does not remove enough of it, you may get sick. A high level of uric acid in the body is called hyperuricemia and can lead to gout or kidney damage.
This test may also be done to check if a high level of uric acid is causing kidney stones.
Normal values range from 250 to 750 milligrams per 24 hours.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
A high uric acid level in the urine may be due to:
- Body not able to process purine (Lesch-Nyhan syndrome)
- Cancers that have spread (metastasized)
- Disease that results in breakdown of muscle fibers (rhabdomyolysis)
- Disorders that affect the bone marrow (myeloproliferative disorder)
- Fanconi syndrome
- High-purine diet
Low acid levels in the urine may be due to:
- Kidney is not able to get rid of uric acid well, which can lead to gout or kidney damage
- Kidneys not able to filter fuilds and waste (chronic glomerulonephritis)
- Lead poisoning
- Long-term (chronic) alcohol use
There are no risks with this test.
Gerber GS, Brendler CB. Evaluation of the urologic patient: history, physical examination, and urinalysis. In: Wein AJ, Kavoussi LR, Novick AC, et al., eds. Campbell-Walsh Urology. 10th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 3.
Israni AK, Kasiske BL. Laboratory assessment of kidney disease: glomerular filtration rate, urinalysis, and proteinuria. In: Taal MW, Chertow GM, Marsden PA, et al., eds. Brenner and Rector’s The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 25.
McPherson RA, Ben-Ezra J. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 28.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.