Uric Acid in Blood
Test OverviewThe blood uric acid test measures the amount
of
uric acid in a blood sample. Uric acid is produced
from the natural breakdown of your body's cells and from the foods you
eat. Most of the uric acid is filtered out by the kidneys and
passes out of the body in urine. A small amount passes out of the body in
stool. But if too much uric acid is being produced or if the kidneys are not
able to remove it from the blood normally, the level of uric acid in the blood
increases. High levels of uric acid in the blood can cause solid
crystals to form within joints. This causes a painful condition called
gout. If gout remains untreated, these uric acid
crystals can build up in the joints and nearby tissues, forming hard lumpy
deposits called
tophi. High levels of uric acid may also cause
kidney stones or
kidney failure. Why It Is DoneA uric acid blood test is done
to: - Help diagnose gout.
- Check to see if
kidney stones may be caused by high uric acid levels in the
body.
- Check to see if medicine that decreases uric acid levels is
working.
- Check uric acid levels in people who are undergoing
chemotherapy or
radiation therapy. These treatments destroy cancer
cells that then may leak uric acid into the blood.
How To PrepareYou do not need to do anything before
you have this test. Some medicines can change the results of this
test. Be sure to tell your doctor about all the nonprescription 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 DoneThe health professional who takes a
sample of your blood will: - Wrap an elastic band around your upper arm to stop the flow of
blood. This makes the veins below the band larger so it is easier to put a
needle into the vein.
- Clean the needle site with
alcohol.
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure on the site and then put on a
bandage.
How It FeelsThe blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
pinch. RisksThere is very little chance of a problem from
having a blood sample taken from a vein. - You may get a small bruise at the site. You can lower the chance
of bruising by keeping pressure on the site for several minutes.
- In
rare case, the vein may become swollen after the blood sample is taken. This
problem is called phlebitis. A warm compress can be used several times a day to
treat this.
ResultsThe blood uric acid test measures the
amount of uric acid in a blood sample. NormalThe normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab. Results are usually ready in 1 to 2 days. Uric acid crystals sometimes form in
joints even at levels less than 7 mg/dL, especially in men. This can lead to a
gout attack, even though the uric acid levels are
within the normal range. 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 TestHigh valuesHigh uric acid values may be caused
by: - Individual differences in the way your body
produces or gets rid of uric acid.
- Conditions, such as:
- Kidney disease or kidney
damage.
- The increased breakdown of body cells that occurs with some
types of cancer (including
leukemia,
lymphoma, and
multiple myeloma) or cancer treatments,
hemolytic anemia,
sickle cell anemia, or
heart failure.
- Other disorders, such as
alcohol dependence,
preeclampsia, liver disease (cirrhosis),
obesity,
psoriasis,
hypothyroidism, and low blood levels of
parathyroid hormone.
- Starvation,
malnutrition, or
lead poisoning.
- A rare inherited gene disorder called Lesch-Nyhan
syndrome.
- Medicines, such as some
diuretics, vitamin C (ascorbic acid), lower doses of
aspirin (75 to 100 mg daily), niacin, warfarin (such as Coumadin),
cyclosporine, levodopa, tacrolimus, and some medicines used to treat
leukemia,
lymphoma, or
tuberculosis.
- Eating foods that are very high in
purines, such as organ meats (liver, brains), red
meats (beef, lamb), game meat (deer, elk), some seafood (sardines, herring,
scallops), and beer.
Low valuesLow uric acid values may be caused
by: - Severe liver disease,
Wilson's disease, or some types of
cancer.
- The syndrome of inappropriate antidiuretic hormone (SIADH),
a condition that causes large amounts of fluid to build up in the
body.
- Not eating enough protein.
- Sulfinpyrazone, large
amounts of aspirin (1,500 mg or more daily), probenecid (such as Probalan), and
allopurinol (such as Zyloprim).
What To Think About- A high level of uric acid in the blood does not always
mean that a person with a painful joint has gout. Testing the fluid taken from
an affected joint for the presence of uric acid crystals is the only sure
method to diagnose gout. To learn more, see the topic
Joint Fluid Analysis.
- Having a high level of uric acid in your blood and recurrent urate kidney stones or chronic kidney disease may need treatment to avoid kidney problems.
- Uric acid may also
be measured in urine. If your blood uric acid level is high, a 24-hour urine
collection may help your doctor find out whether your body is producing too much uric acid
or your kidneys are not getting rid of enough of it. To learn more, see
the topic
Uric Acid in Urine.
- Uric acid blood levels
vary from day to day. The level is usually higher in the morning and lower in
the evening.
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
Adam Husney, MD - Family Medicine
E. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerMartin J. Gabica, MD - Family Medicine Current as ofJanuary 30, 2017 Current as of:
January 30, 2017 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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