A high concentration of uric acid in the blood, called hyperuricemia, can be associated with arthritic gout as well as other medical conditions, such as hypertension. Many health professionals recommend treating hyperuricemia through diet, lifestyle changes, and/or medication.
This page explains what uric acid is, how hyperuricemia develops, its association with gout and other diseases, and how to lower uric acid levels in the blood.
The body produces uric acid when it breaks down purines. Purines are organic chemicals naturally found in the cells of humans as well as foods. After the body breaks down purines, uric acid enters the bloodstream.
Uric acid is not necessarily bad—in fact, in certain settings of the body, it can act as an antioxidant.1,2 Most uric acid is processed by the kidneys and excreted in the urine. Some is excreted in the stool.
How Hyperuricemia Develops
It is normal to have a low level of uric acid in the bloodstream. Uric acid levels may get too high when one or more of the following occurs:
- The kidneys are not able to adequately filter and flush out uric acid from the bloodstream
- A person eats foods and beverages that are high in purines
- The body produces too much uric acid
When the body produces too much uric acid, there is typically a genetic cause.
Hyperuricemia and Gout
When hyperuricemia occurs, the excess uric acid can deposit in joints, where it can form uric acid crystals, also called urate crystals. These crystals can cause joint irritation and spur an immune system response that causes joint inflammation. The resulting joint pain, swelling, redness, and warmth are called a gout attack or flare.
Most people who have hyperuricemia do not have gout. In fact:
- Experts estimate that more than 21% of the general population has hyperuricemia while just 4% has gout.3
- It is possible to have hyperuricemia and uric acid crystals in the joints but experience none of the inflammatory symptoms of gout.
These facts suggest that hyperuricemia may be just one contributing factor to the development of gout.4 Researchers are investigating why some people with hyperuricemia develop gout while others do not.
Hyperuricemia does not lead to pseudogout
Unlike gout, pseudogout is not associated with hyperuricemia. Pseudogout is caused by calcium phosphate crystals and produces symptoms similar to gout.
Hyperuricemia and Other Medical Conditions
People who have hyperuricemia—whether it is symptomatic or asymptomatic—are more likely to have other medical problems. It is unclear whether hyperuricemia contributes to the development or worsening of these diseases.
Conditions associated with hyperuricemia include but are not limited to:
Chronic kidney disease
When uric acid crystals form, they can collect in the kidney and cause kidney stones. (There are different types of kidney stones; uric acid stones are just one type.) Experts estimate that among people who have gout, nearly 14% report having had kidney stones.5
Hypertension (high blood pressure)
High levels of uric acid are known to be associated with high blood pressure. Limited evidence suggests that treating hyperuricemia may prevent or postpone the development of hypertension.4
Some blood pressure medications can increase uric acid levels in the blood.
Coronary artery disease and congestive heart failure are both associated with hyperuricemia. One study found that about half of patients who were hospitalized or died of heart failure also had hyperuricemia.6
Some researchers theorize that an enzyme that produces uric acid—not uric acid itself—is associated with coronary artery disease.4
Type 2 diabetes
Asymptomatic hyperuricemia is associated with type 2 diabetes. Some researchers theorize that uric acid levels may affect how the pancreas works and worsen insulin resistance.4
More research is needed to understand the connection between the above medical conditions and hyperuricemia.
It is possible to measure the amount of uric acid in the blood and urine. Diagnosis typically involves a blood sample, and the measurement is often expressed in milligrams of uric acid per deciliter of blood (mg/dL). A diagnosis of hyperuricemia is considered in7,8:
- Men who have more than 7.0 mg/dL
- Women who have more than 6.0 mg/dL
It is important to note that uric acid levels in the blood naturally fluctuate, and what is considered "normal" may vary depending on the lab doing the analysis.
Not a routine test
Unlike lab tests for blood cell counts and cholesterol, a lab test to measure uric acid concentrations is not considered routine in North America and Europe.4 A doctor will typically only order this test if they have a reason—for example, they suspect a patient has or is at risk of gout.
Signs and symptoms of hyperuricemia are typically associated with urate crystals found in the joints, tendons, or kidneys.2 People who have abnormally high uric acid levels and no symptoms or signs of urate deposition are said to have asymptomatic hyperuricemia.9
Whether or not to treat hyperuricemia—and how to treat it—typically depends on whether it causes symptoms.
- If hyperuricemia triggers gout attacks, medical treatment is recommended.
- Immediate treatment to lower uric acid levels can ease the symptoms of an ongoing gout attack.
- Regular medication and certain lifestyle changes can lower the levels of uric acid in the body, reducing the risk of future gout attacks.
- If hyperuricemia does not cause signs or symptoms (asymptomatic hyperuricemia), the treatment recommendations are less clear.
- Using uric-acid lowering medications to treat asymptomatic hyperuricemia may have a positive impact on health, but this idea is controversial.4 Long-term use of these medications carries potential side effects and health risks.9
- While the use of medication is controversial, many doctors agree that even asymptomatic hyperuricemia is a sign that lifestyle changes should be made.
Read more about Gout Treatment
Lifestyle changes that can lower hyperuricemia include:
- Eating a whole foods, plant-based diet that is low in purines.
- Losing excess weight through diet and exercise may help lower uric acid levels in the blood.10
- Getting regular exercise and avoiding a sedentary lifestyle. Research suggests that doing these two things—independent of weight loss—may reduce the risk of hyperuricemia.11,12
People who are interested in treating hyperuricemia through diet are advised to learn about purines, which are found in foods and drinks. Experts estimate a low purine diet can reduce uric acid levels up to 15%.9