What is a Uric Acid Blood Test?

Your body is in constant motion, 24-7. Even as you sleep, your blood flows, your brain fires away, and your gut digests that late-night snack. Whenever you eat something, your body pulls out the good stuff, such as proteins and vitamins, and sends away the waste.

Typically, one of those waste products is uric acid. It’s formed when your body breaks down purines, which are found in some foods, but also show up when cells die and get taken apart. Most of the uric acid leaves your body when you pee, and some when you poop.

So if you have high levels of uric acid, it can be a sign of disease such as gout. That’s when you might need a uric acid blood test, which measures how much uric acid you have in your blood.

You may also hear this test called a serum uric acid test, serum urate, or UA.

Why Would I Need It?

Your doctor can use this test to help find out if you have:

Gout: This is a form of arthritis where crystals from uric acid form in your joints and cause intense pain. You often feel it in your big toe, but can get it in your ankles, feet, hands, knees, and wrists, as well. It can also cause swelling, redness, and discomfort in those joints, and may limit your range of motion.

Kidney stones: These are little, hard masses -- like small stones -- that form in your kidneys when you have too much uric acid. They may cause severe pain in your lower back that comes and goes, blood in your urine, throwing up, upset stomach, and an urgent need to pee.

High uric acid level during chemo or radiation: These treatments kill a lot of cells in your body, which can raise the level of uric acid. The test is used to check that your level doesn’t get too high.

You can also have a low level of uric acid, but your doctor would typically order other tests to look into what’s causing that.

Continued

How Do I Get Ready for the Test?

Typically, you don’t need to do anything special. In some cases, your doctor may tell you not to eat or drink anything for 4 or more hours before the test. Your doctor will also let you know if you need to stop taking any medicines.

Make sure to tell your doctor about any medicines, herbs, and supplements you take, including over-the-counter, prescription, and illegal drugs. Any of these, including medications that make you pee more often (diuretics), vitamin B-3, and aspirin, can affect your results.

How’s the Test Done?

This test is a basic blood draw and takes just a few minutes. A lab tech will:

  • Clean the skin where the needle goes in
  • Wrap a rubber strap around your upper arm -- this creates pressure to make your veins swell with blood
  • Put a thin needle into a vein, usually on the inside of your arm at your elbow or in the back of your hand
  • Draw the blood
  • Remove the rubber strap and put a bandage on your arm or hand

Are There Any Risks?

Typically, you’ll feel a prick when the needle goes in. That’s usually the worst of it, but since you’re having your blood drawn, there’s a very slight chance of problems such as:

  • Bleeding or bruising
  • Feeling dizzy or lightheaded
  • Infection

What Does the Result Mean?

The test tells you how much uric acid is in your blood.

It measures the uric acid in milligrams (mg) and the blood in deciliters (dL), so you’ll see a number with units of mg/dL.

What’s a normal range varies with different labs, so check with your doctor to help you understand your result. You usually get results in 1 to 2 days, but it depends on your lab.

Generally, your uric acid level is high when:

  • For females, it’s over 6 mg/dL
  • For males, it’s over 7 mg/dL

High levels could be a sign of many conditions, including gout, kidney disease, and cancer. But it could be higher than normal because you eat foods with a lot of purines. That includes dried beans or certain fish such as anchovies, mackerel, and sardines.

Usually, your doctor will order other tests at the same time to track down what’s causing your symptoms. Your doctor will then help you understand what all your results mean and what your next steps are.

Continued

What Other Tests Might I Need?

Based on your symptoms and what your doctor’s looking for, you may get:

  • More tests for gout, including one where they take fluid from the joint with symptoms
  • Urinalysis, a urine test that looks for more signs of kidney stones, including blood, white blood cells, and crystals in your pee

If you don’t seem to have gout or kidney stones, your doctor may order more blood or urine tests to look into what else might be triggering high uric acid levels.

WebMD Medical Reference Reviewed by William Blahd, MD on January 27, 2017

Sources

SOURCES:

University of Rochester Medical Center: “Uric Acid (Blood).”

KidsHealth: “Blood Test: Uric Acid.”

Lab Test Online: “Uric Acid, “Kidney Stone Analysis.”

Mayo Clinic: “Gout.”

NIH, National Institute of Diabetes and Digestive and Kidney Diseases: “Diet for Kidney Stone Prevention.”

Scripps: “Uric Acid: Blood.”

© 2017 WebMD, LLC. All rights reserved.

Pagination