Health Encyclopedia

Uric acid - urine

Definition

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas, beer, and wine. Purines are also a part of normal body substances, such as DNA.

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 doesn't remove enough of it, you may get sick. High levels of uric acid in the body is called hyperuricemia.

This test checks to see how much uric acid you have in your urine.

How the test is performed

A 24-hour urine sample is needed. See: 24-hour urine collection.

How to prepare for the test

Your doctor may tell you to stop taking any drugs that may affect the test results. For example, high levels of vitamin C and dyes used during certain x-rays may cause incorrect results.

Drugs that can interfere with test results include:

Alcohol
Allopurinol
Anti-inflammatory drugs (such as ibuprofen)
Salicylates (including aspirin)
Thiazide diuretics
Probenecid

This list may not be all-inclusive.

How the test will feel

The test involves only normal urination, and there is no discomfort.

Why the test is performed

This test may be done to diagnose the cause of kidney stones. It may also be used to monitor people with gout, since many of these patients develop uric acid kidney stones.

Normal Values

Normal values range from 250 to 750 milligrams per 24 hours.

Note: 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

Higher than normal uric acid levels in the urine may be due to:

Cancers that have spread (metastasized)
Disorders that affect the bone marrow or certain white blood cells
High-purine diet
Gout
Rhabdomyolysis
Lesch-Nyhan syndrome
Fanconi syndrome

Lower than normal uric acid levels in the urine may be due to:

Long-term alcohol use
Chronic glomerulonephritis
Lead poisoning

References

McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. St. Louis, Mo: WB Saunders; 2006.

Bazari H. Approach to the patient with renal disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 115.

Review Date:8/10/2009
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, Medical Director, A.D.A.M., Inc.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.