Uric acid – blood
Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks. These include liver, anchovies, mackerel, dried beans and peas, and beer.
Most uric acid dissolves in blood and travels to the kidneys. From there, it passes out in urine. If your body produces too much uric acid or doesn’t remove enough if it, you can get sick. A high level of uric acid in the blood is called hyperuricemia.
This test checks to see how much uric acid you have in your blood. Another test can be used to check the level of uric acid in your urine.
How the Test is Performed
A blood sample is needed. Most of the time blood is drawn from a veinf located on the inside of the elbow or the back of the hand.
How to Prepare for the Test
You should not eat or drink anything for 4 hours before the test unless told otherwise.
Many medicines can interfere with blood test results.
- Your health care provider will tell you if you need to stop taking any medicines before you have this test.
- Do not stop or change your medications without talking to your doctor first.
Your doctor may also tell you to stop taking any drugs that may affect the test results. Never stop taking any medicine without talking to your doctor.
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 arthritis
- bone marrow disorders, such as leukemia
- a diet high in purines
- hypoparathyroidism, which is a decrease in your parathyroid function
- 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
Causes of High uric acid level
A high uric acid level can be caused when your body either produces too much uric acid or your kidneys don’t eliminate uric acid rapidly enough.
A high uric acid level may cause increasingly frequent attacks of gout, or it may never cause problems. A high uric acid level may also cause some people to develop kidney stones or kidney failure. And some people with a high uric acid level also develop high blood pressure, heart disease or chronic kidney disease, but it’s often unclear whether this is a direct cause or merely an early warning sign of these conditions.
Factors that may cause a high uric acid level in your blood include:
- Diuretic medications (water pills)
- Drinking too much alcohol
- Genetics (inherited tendencies)
- Hypothyroidism (underactive thyroid)
- Immune-suppressing drugs
- Niacin, or vitamin B-3
- Purine-rich diet organ meat, game meat, anchovies, herring, gravy, dried beans, dried peas, mushrooms and other foods
- Renal insufficiency inability of the kidneys to filter waste
- Tumor lysis syndrome a rapid release of cells into the blood caused by certain cancers or by chemotherapy for those cancers
What are some symptoms of hyperuricemia to look for?
- You may not have any symptoms.
- If your blood uric acid levels are significantly elevated, and you are undergoing chemotherapy for leukemia or lymphoma, you may have symptoms kidney problems, or gouty arthritis from high uric acid levels in your blood.
- You may have fever, chills, fatigue if you have certain forms of cancer, and your uric acid levels are elevated (caused by tumor lysis syndrome)
- You may notice an inflammation of a joint (called “gout”), if the uric acid crystals deposit in one of your joints. (*Note- gout may occur with normal uric acid levels, too).
- You may have kidney problems (caused by formation of kidney stones), or problems
Is there anything else I should know?
Many drugs can increase or decrease the level of uric acid. In particular, diuretic drugs like thiazide drugs can cause uric acid levels to go up.
Aspirin and other salicylates have varying effects on uric acid. At low aspirin levels (as may occur in persons taking aspirin only occasionally), aspirin can increase blood uric acid. On the other hand, in high doses (as may be used to treat rheumatoid arthritis), aspirin actually lowers the concentration of uric acid.
For people who have uric acid kidney stones or gout, foods that are high in purine content should be avoided, including organ meats (like liver and kidneys), sardines and anchovies. Alcohol also should be avoided, because it slows down the removal of uric acid from the body. Fasting, rapid weight loss, stress, and strenuous exercise all raise uric acid levels.
Although the uric acid test cannot definitively diagnose gout, a test for monosodium urate in synovial fluid (joint fluid) can.
Some people may have a high level of uric acid in the blood without having associated signs or symptoms (asymptomatichyperuricemia). However, general screening to detect this condition is not recommended, nor is treatment considered appropriate.