What is a uric acid test?

This test measures the amount of uric acid in your blood or urine. Uric acid is a normal waste product that's made when the body breaks down chemicals called purines. Purines are substances found in your own cells and also in some foods. Foods with high levels of purines include liver, anchovies, sardines, dried beans, and beer.

Most uric acid dissolves in your blood, then goes to the kidneys. From there, it leaves the body through your urine. If your body makes too much uric acid or doesn't release enough into your urine, it can make crystals that form in your joints. This condition is known as gout. Gout is a form of arthritis that causes painful inflammation in and around the joints. High uric acid levels can also cause other disorders, including kidney stones and kidney failure.

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

What is it used for?

A uric acid test is most often used to:

• Help diagnose gout
• Help find the cause of frequent kidney stones
• Monitor the uric acid level of people undergoing certain cancer treatments. Chemotherapy and radiation therapy can cause high levels of uric acid to go into the blood.

Why do I need a uric acid test?

You may also need a uric acid test if you have symptoms of gout. These include:

• Pain and/or swelling in the joints, especially in the big toe, ankle, or knee
• Reddish, shiny skin around the joints
• Joints that feel warm when touched

You may also need this test if you have symptoms of a kidney stone. These include:

• Sharp pains in your abdomen, side, or groin
• Back pain
• Blood in your urine
• Frequent urge to urinate
• Pain when urinating
• Cloudy or bad-smelling urine
• Nausea and vomiting

In addition, you may need this test if you are undergoing chemotherapy or radiation therapy for cancer. These treatments can raise uric acid levels. The test can help make sure you get treated before levels get too high.

What happens during a uric acid test?

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

During 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 urine passed in a 24-hour period. This is called a 24-hour urine sample test. Your health care provider or a laboratory professional will give you a container to collect your urine and instructions on how to collect and store your samples. A 24-hour urine sample test generally includes the following steps:

• Empty your bladder in the morning and flush that urine away. Record the time.
• For the next 24 hours, save all your urine passed in the container provided.
• Store your urine container in the refrigerator or a cooler with ice.
• Return the sample container to your health provider's office or the laboratory as instructed.

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

You don't need any special preparations for a uric acid blood test. Be sure to carefully follow all the instructions for providing a 24-hour urine sample.

Are there any risks to the test?

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