Uric Acid (Blood)
Testing your uric acid
This test measures the amount of uric acid in your blood.
Uric acid is a normal body waste product. It forms when chemicals called purines break down. Purines are a natural substance found in the body. They are also found in many foods such as liver, shellfish, and alcohol. They can also be formed in the body when DNA is broken down.
When purines are broken down to uric acid in the blood, the body gets rid of it when you urinate or have a bowel movement. But if your body makes too much uric acid, or if your kidneys aren't working well, uric acid can build up in the blood. Uric acid levels can also increase when you eat too many high-purine foods or take medicines like diuretics, aspirin, and niacin. Then crystals of uric acid can form and collect in the joints. This causes painful inflammation. This condition is called gout.
Why do I need this test?
You may need this test if your healthcare provider wants to see if you have high levels of uric acid in your blood. Your healthcare provider may advise this test if you have symptoms of gout, although most people with hyperuricemia don't develop gout. Symptoms of gout include:
Joint pain or soreness
Swelling in a joint or red skin around a joint
Swelling and pain in a big toe, ankle, or knee
Joints that are hot to the touch
Swelling and pain that affects only 1 joint in the body
Skin that looks shiny and is red or purple
You may also need this test if you have symptoms of kidney stones. Symptoms include:
Severe pain along your lower back. This may repeatedly get worse and then get better. The pain may also travel to your genitals.
Nausea
Vomiting
Urgent need to urinate
Blood in your urine
What other tests might I have along with this test?
You may have other tests to check for gout. For example, you may have a sample of joint fluid drawn out with a needle.
You may also have a urinalysis if your healthcare provider thinks that you have a kidney stone. The urinalysis looks for blood, white blood cells, and crystals.
You may have tests of your blood and urine to find out what's causing the high levels uric acid.
What might affect my test results?
Some medicines may affect your test results. These include:
Aspirin and other medicines that contain salicylate
Cyclosporine, a medicine sometimes used for autoimmune diseases
Levodopa, a medicine used to treat Parkinson disease
Some diuretic medicines such as hydrochlorothiazide
Vitamin B-3 (niacin)
Other things that may affect your test results include:
Vigorous exercise
Chemotherapy or radiation therapy to treat cancer
source from University of Rochester medical center website