Uric Acid in Urine
Test OverviewThe uric acid urine test measures the amount
of
uric acid in a sample of urine collected over 24
hours. Uric acid is made from the natural breakdown of your body's cells. It's also made
from the foods you eat. Your kidneys take uric acid out of your blood and put it into urine so that it can leave your body. But if your body is making too
much uric acid, the level in the urine can get too high. And if your kidneys aren't working the way they should, the level of uric
acid in the urine can get too low. High levels of uric acid can cause crystals to form in joints. This causes a painful
problem called
gout. If gout isn't treated, the crystals
can build up and form hard lumpy deposits
called
tophi. High uric acid levels can also cause
kidney stones. Why It Is DoneThis test is done
to: - See if kidney stones were caused by
high uric acid levels.
- Find the cause of a high level
of uric acid in the blood and help choose the proper treatment.
How To PrepareNo special preparation is needed. You don't need to limit liquids or
foods before the test. Make sure you drink enough liquids during the 24-hour test so that you don't get dehydrated. During the 24-hour period, don't drink alcohol. It lowers the amount of uric acid
eliminated by the kidneys. Many medicines can change the results
of this test. Be sure to tell your doctor about all the over-the-counter and
prescription medicines you take. Talk to your doctor about any
concerns you have regarding the need for the test, its risks, how it will be
done, or what the results may mean. To help you understand the importance
of this test, fill out the
medical test information form(What is a PDF document?).
How It Is DoneA uric acid urine test is usually done at home. You must collect all the urine you produce in a 24-hour period. - You start collecting your urine in the morning.
When you first get up, empty your bladder. But do not save this urine. Write
down the time that you urinated to mark the beginning of your 24-hour
collection period.
- For the next 24 hours, collect all of your urine.
Your doctor or lab will usually provide you with a large container that holds
about 1 gal (4 L). The
container has a small amount of preservative in it. Urinate into a small, clean
container. Then pour the urine into the large container. Don't touch the
inside of the container with your fingers.
- Keep the large container
in the refrigerator when you aren't using it.
- Empty your bladder for the
last time at or just before the end of the 24-hour period. Add this urine to
the large container, and record the time.
- Do not get toilet paper,
pubic hair, stool (feces), menstrual blood, or other foreign matter in the
urine sample.
How It FeelsTaking a 24-hour urine sample does not cause pain. RisksA 24-hour urine sample doesn't cause any problems. ResultsThe uric acid urine test measures the
amount of
uric acid in a sample of urine collected over 24
hours. These numbers are just a guide. The range for "normal" varies from lab to lab. Your lab may have a different range. Your lab report should show what range your lab uses for "normal." Also, your doctor will evaluate your results based on your health and other factors. So a number that is outside the normal range here may still be normal for you. Results are usually available in 1 to 2 days. Women typically have slightly lower uric acid
levels than men. Many conditions can change uric acid
levels. Your doctor will talk with you about any abnormal results that may be
related to your symptoms and past health. What Affects the TestTest results might not be accurate if you don't collect exactly 24 hours of urine. There are many things that can cause your level of uric acid to be too high or too low. High valuesHigh uric acid levels may be caused
by conditions such as: - Kidney disease or kidney
damage.
- Some
types of cancer (including
leukemia,
lymphoma, and
multiple myeloma) or cancer treatments.
- Hemolytic anemia,
sickle cell anemia, or
heart failure.
- Disorders such as
alcohol dependence,
preeclampsia, liver disease (cirrhosis),
lipid disorders,
obesity,
psoriasis,
hypothyroidism, and low blood levels of
parathyroid hormone.
- Starvation,
malnutrition, or
lead poisoning.
- A rare inherited gene disorder called Lesch-Nyhan
syndrome.
High levels may also be caused by: - Certain medicines. These include some
diuretics, vitamin C (ascorbic acid), lower doses of
aspirin (75 to 80 mg aspirin daily), niacin, and some medicines used to treat
leukemia, lymphoma, and
tuberculosis.
- Contrast material used for some
X-ray tests.
- Eating foods that are very high in
purines. These include organ meats (liver, brains), red
meats (beef, lamb), game meat (deer, elk), and some seafood (sardines, herring,
scallops).
- Drinking a lot of alcohol, especially beer.
Low valuesLow uric acid levels may be caused
by: - Gout.
- Kidney damage or
disease.
- Folic acid deficiency or lead
poisoning.
- Not eating enough protein.
- Some medicines, such as allopurinol,
insulin, some diuretics, and high levels of aspirin.
- Drinking
alcohol during the collection period.
What To Think About- Having a high uric acid level doesn't always mean you have
gout. You won't need treatment as long as you don't have symptoms.
- If you have kidney disease or have had a
problem with kidney stones, your doctor may start treatment with a medicine,
such as allopurinol, even if your uric acid levels are not too
high.
- A person with tophi or uric acid kidney stones
will be treated for high uric acid levels no matter what the results of the
uric acid test are.
- Uric acid also may be measured in blood. To learn more, see the topic
Uric Acid in Blood.
ReferencesCitations- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Other Works Consulted- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.
CreditsByHealthwise Staff
Primary Medical ReviewerAnne C. Poinier, MD - Internal Medicine
Specialist Medical ReviewerNancy Ann Shadick, MD, MPH - Internal Medicine, Rheumatology Current as ofOctober 14, 2016 Current as of:
October 14, 2016 Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins. Last modified on: 8 September 2017
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