Uric Acid and the Uric Acid Blood Test
A uric acid blood test, also known as a serum uric acid
measurement, determines how much uric acid is present in your blood. The test
can help determine how well your body produces and removes uric acid.
Uric acid is a chemical produced when your body breaks down foods
that contain organic compounds called purines. Foods and beverages with a high
purine content include:
- dried beans
Purines are also created through the natural process of cell breakdown
in the body.
Most uric acid is dissolved in the blood, filtered through the
kidneys, and expelled in the urine. Sometimes, the body produces too much uric
acid or doesn’t filter out enough of it. Hyperuricemia is the name of the disorder that occurs when
you have too much uric acid in your body.
High levels of uric acid are associated with a condition called
gout. Gout is a form of arthritis that causes swelling of the joints, especially
in the feet and big toes. Another cause of hyperuricemia is increased cell
death, due to cancer or cancer treatments. This can lead to an accumulation of
uric acid in the body.
It’s also possible to have too little uric acid in your blood,
which is a symptom of liver or kidney disease. It’s also a symptom of Fanconi
syndrome, a disorder of the kidney tubules that prevents the absorption of
substances such as glucose and uric acid. These substance are then passed in
the urine instead.
Purposes of a Uric Acid Blood Test
Most commonly, the test is used to:
- diagnose and monitor people with gout
- monitor people who are undergoing chemotherapy
or radiation treatment
- check kidney function after an injury
- find the cause of kidney stones
- diagnose kidney disorders
You may need a uric acid test if:
- you have joint pain or swelling that may be related
- you’re currently undergoing chemotherapy
- you’re about to start chemotherapy
- you have frequent kidney stones
- you’ve been diagnosed with gout in the past
Another option for uric acid testing is to test your urine over a
24-hour period. Sometimes your doctor will recommend both to confirm a
Preparing for a Uric Acid Blood Test
The following may interfere with your uric acid test results:
- certain medications, such as aspirin and
- high levels of vitamin C
- dyes used in X-ray tests
Tell your doctor about any prescription or over-the-counter
medications or supplements you’re taking.
You may need to fast (refrain from eating or drinking) for four
hours before the test.
How a Uric Acid Blood Test Is Done
The process of obtaining a blood sample for testing is called
Your doctor or another healthcare provider will take blood from a
vein, usually from your inner elbow or the back of your hand. First, they’ll sterilize
the area with an antiseptic. They will then wrap an elastic band around your
arm to allow blood to fill the veins.
Then, they’ll insert a needle into your vein. The blood will be
collected in an attached vial. Once the blood has been collected, the plastic
band will be untied and the needle will be removed from the vein. Pressure will
be applied to the site of the needle entry and a bandage will be applied if
For infants and young children, a small cut may be made on the
arm and a test strip or slide used to collect a small sample of blood. The area
is then cleaned and bandaged if necessary.
Once collected, the blood is sent to a laboratory for
What Do the Test Results Mean?
Uric acid levels can vary based on gender. According to the Clinical Reference
Laboratory (CRL), normal values for women are 2.5 to 7.5 milligrams/deciliter
(mg/dL) and 4.0 to 8.5 mg/dL for men. However, the values may vary based on the
lab doing the testing.
According to the American
College of Rheumatology (ACR), your target level if you have gout is a
blood uric acid level of less than 6 mg/dL. Low levels of uric acid are less
common than high levels and are less of a health concern.
High levels of uric acid in your blood typically indicate that
your body is making too much uric acid or that your kidneys aren’t removing
enough uric acid from your body. Having cancer or undergoing cancer treatment can
also raise your uric acid levels.
High uric acid levels in your blood can also indicate of a
variety of conditions, including:
- gout, which involves recurring attacks of acute
- bone marrow disorders, such as leukemia
- a diet high in purines
- hypoparathyroidism, which is a decrease in your parathyroid
- kidney disorders, such as acute kidney failure
- kidney stones
- multiple myeloma, which is cancer of the plasma
cells in your bone marrow
- metastasized cancer, which is cancer that has
spread from its original site
The blood uric acid test isn’t considered a definitive test for
gout. The only test that can absolutely confirm the presence of gout is testing
a person’s joint fluid for monosodium urate. However, your doctor can make an
educated guess based on high blood levels and your gout symptoms. Also, it’s
possible to have high uric acid levels without the symptoms of gout. This is
known as asymptomatic hyperuricemia.
Low levels of uric acid in the blood may suggest:
- Wilson’s disease, which is an inherited disorder
that causes copper to build up in your body tissues
- Fanconi syndrome, which is a kidney disorder
- liver or kidney disease
- a diet low in purines
The Risks of a Uric Acid Blood Test
Blood draws are routine and very safe. The risks associated with
a uric acid blood test are the same as those associated with any blood draw.
Uric acid blood tests may cause:
- pain or discomfort at the puncture site
- fainting or lightheadedness
- an accumulation of blood under your skin, such
as hematoma or bruising
- infection at the puncture site
If you experience significant bleeding that won’t stop after the
blood test, seek emergency medical treatment. However, this is a rare
occurrence, as are the other complications noted here.
After the Uric Acid Test
Your uric acid blood test results can help determine what
treatments are appropriate. In some cases, you may not need treatment.
If your doctor diagnoses you with gout, this could include taking
medicines to reduce pain and swelling. Dietary changes to cut back on purines
can also help. Changing your diet can also benefit you if you have chronic uric
acid kidney stones. If you’re undergoing different chemotherapy treatments, you
may need frequent blood test monitoring to make sure your uric acid levels
don’t become too high.