The blood uric acid test measures the amount
uric acid in a blood sample. Uric acid is produced
from the natural breakdown of your body's cells and from the foods you
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
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
tophi. High levels of uric acid may also cause
kidney stones or
Why It Is Done
A uric acid blood test is done
Help diagnose gout.
Check to see if
kidney stones may be caused by high uric acid levels in the
Check to see if medicine that decreases uric acid levels is
Check uric acid levels in people who are undergoing
radiation therapy. These treatments destroy cancer
cells that then may leak uric acid into the blood.
How To Prepare
You 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 Done
The 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
Put the needle into the vein. More than one needle stick
may be needed.
Attach a tube to the needle to fill it with
Remove the band from your arm when enough blood is
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
How It Feels
The 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
There 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.
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
Ongoing bleeding can be a problem for people with
bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning
medicines can make bleeding more likely. If you have bleeding or clotting
problems, or if you take blood-thinning medicine, tell your doctor before your
blood sample is taken.
The blood uric acid test measures the
amount of uric acid in a blood sample.
The 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.
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 Test
High uric acid values may be caused
Individual differences in the way your body
produces or gets rid of uric acid.
Conditions, such as:
Kidney disease or kidney
The increased breakdown of body cells that occurs with some
types of cancer (including
multiple myeloma) or cancer treatments,
sickle cell anemia, or
Other disorders, such as
preeclampsia, liver disease (cirrhosis),
hypothyroidism, and low blood levels of
A rare inherited gene disorder called Lesch-Nyhan
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
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 uric acid values may be caused
Severe liver disease,
Wilson's disease, or some types of
The syndrome of inappropriate antidiuretic hormone (SIADH),
a condition that causes large amounts of fluid to build up in the
Not eating enough protein.
amounts of aspirin (1,500 mg or more daily), probenecid (such as Probalan), and
allopurinol (such as Zyloprim).
What To Think About
Having a high uric acid level does not mean
that you have gout. If your uric acid level is high and you do not have any
other symptoms, you will not need to take any medicine to decrease your uric
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.
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
Uric Acid in Urine.
Uric acid blood levels
vary from day to day. The level is usually higher in the morning and lower in
Blood uric acid levels that increase during pregnancy,
even if the levels remain within the normal range, may help diagnose
How this information was developed to help you make better health decisions.