Uric Acid Test

What is a uric acid test?

A uric acid test measures the amount of uric acid in a sample of your blood or urine (pee). Uric acid is a normal waste product that your body makes when it breaks down chemicals called purines. These chemicals come from your cells when they die and can be found in certain foods and beverages. 

Normally, uric acid dissolves in your blood and is filtered out by the kidneys. It then exits your body through your urine. But if your body makes too much uric acid or your kidneys don't remove enough of it, uric acid can build up in your blood. When that happens, it can form needle-shaped crystals in and around your joints. This condition is called gout. 

Gout is a type of arthritis that causes painful swelling in your joints. High uric acid levels can also cause kidney stones, or kidney failure. But not everyone with high levels of uric acid will have these problems.

Other names: serum urate, UA, uric acid: serum and urine 

What is it used for?

A uric acid test can be done using a blood or urine sample.

Auric acid blood test may be used to:

• Help diagnose gout, usually when done with a synovial fluid analysis. Synovial fluid helps keep your joints lubricated.

• Monitor uric acid levels in people who are having cancer chemotherapy or certain other cancer treatments. When treatment kills cancer cells quickly, they release large amounts of purines into the blood. This can lead to serious problems from high uric acid levels. Testing helps catch an increase in uric acid so it can be treated early.

A uric acid urine test may be used to:

• Help find out whether high levels of uric acid are causing kidney stones

• Monitor the risk of developing kidney stones in people who have gout

Why do I need a uric acid test?

You may need a uric acid blood test if you have symptoms of gout or another condition related to abnormal uric acid levels.

Symptoms of gout usually occur in one joint at a time. The big toe is most commonly affected, but your other toes, ankles, or knees may also have symptoms. These can include:

• Intense pain
• Swelling, redness, and/or warmness around the joint
• Limited range of motion

You may also need this test if you:

• Are receiving cancer treatment, since certain therapies can raise uric acid levels as they break down tumor cells
• Have certain cancers that kill cells quickly, such as leukemia
• Have metabolic syndrome, a condition that increases your risk for having high uric acid levels
• Take certain medicines, such as diuretics (a type of medicine that helps your body get rid of excess fluid and salt)

A uric blood blood test may be ordered if you have signs of a kidney stone, such as:

• Sharp pain in your lower abdomen (belly), side, groin or back
• Blood in your urine
• Frequent urge to urinate (pee) 
• Not being able to urinate at all or only urinating a little bit
• Pain when urinating
• Cloudy or bad-smelling urine 
• Nausea and vomiting
• Fever and chills

Your provider may also order testing to monitor your risk of kidney stones if you already have gout or a history of kidney stones.

What happens during a uric acid test?

A uric acid test may be done as a blood test or a urine test. Your provider will decide which test you need.

For a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

For a uric acid urine test, you'll need to collect all your urine during a 24-hour period. This is called a 24-hour urine sample test. You will be given a special container to collect your urine and instructions on how to collect and store your samples. Your provider will tell you what time to start. The test generally includes the following steps:

• To begin, urinate in the toilet as usual. Do not collect this urine. Write down the time you urinated.
• For the next 24 hours, collect all your urine in the container.
• During the collection period, store the urine container in a refrigerator or in a cooler with ice.
• 24 hours after starting the test, try to urinate if you can. This is the last urine collection for the test.
• Return the container with your urine to your provider's office or the laboratory as instructed.

Will I need to do anything to prepare for the test?

Many medicines, including aspirin, can affect uric acid levels in your blood and urine. Taking niacin (vitamin B-3) can also affect your results. So, be sure to tell your provider about all the medicines you take. But don’t stop taking any medicines without talking with your provider first.

Are there any risks to the test?

There is no known risk to having a uric acid blood or urine test.

What do the results mean?

High uric acid levels in a blood test may happen if your body makes too much uric acid or if your kidneys can't properly remove uric acid from your blood. You may also have high levels if you’re eating too many foods that are high in purines, such as:

• Red meat and organ meats, including liver and kidney
• Certain kinds of seafood, including shellfish, anchovies, sardines, trout, and tuna
• Alcohol (all types)
• High fructose corn syrup in soda and sweets

Your provider may order more tests to help diagnose what’s causing the problem. High levels of uric acid may be related to many conditions, including:

• Gout
• Kidney disease or kidney stones
• Leukemia, multiple myeloma, or cancer that has spread in your body (metastatic cancer)
• Side effects from certain cancer treatments, such as chemotherapy
• Alcohol use disorder
• Preeclampsia, a condition that can cause dangerously high blood pressure in pregnant women

Low levels of uric acid in blood are uncommon and usually don’t cause health problems. Health conditions that are related to low uric acid levels are usually diagnosed using other tests.

High uric levels in urine, may be related to:

• Gout
• Kidney stones or having a high risk for kidney stones
• Leukemia, multiple myeloma, or cancer that has spread in your body
• Obesity
• An inherited genetic condition, such as Lesch-Nyhan syndrome, that makes it hard for your body to get rid of uric acid

Low levels of uric acid in urine may be related to kidney disease, lead poisoning, or alcohol use disorder. 

If your results show a high level of uric acid in your blood or urine, it doesn't always mean you have a condition that needs treatment. Many people have high levels of uric acid without having health problems.

If you have questions about your results, talk with your provider. Medicines and/or changes in your diet may help you keep your uric acid levels in a healthy range.

Learn more about laboratory tests, reference ranges, and understanding results.