Hyperuricemia is a medical condition with an elevated concentration of uric acid in the blood. Uric acid is a waste product from the breakdown of purines, compounds found in many foods and also synthesized by the body. The kidneys filter uric acid from the blood, and it is then expelled through urine. Hyperuricemia occurs when the body generates too much uric acid or the kidneys do not eliminate it efficiently. While often asymptomatic initially, the condition can lead to health problems if uric acid levels remain high.
Causes of High Uric Acid
The most frequent cause of hyperuricemia is the under-excretion of uric acid, which accounts for the majority of cases. This involves impaired kidney function, as the kidneys play a large role in filtering uric acid from the blood; about two-thirds of the body’s uric acid is normally excreted through them. When the kidneys cannot perform this function effectively, uric acid is retained. Factors contributing to this issue include chronic kidney disease, certain genetic predispositions, and the use of specific medications, such as diuretics.
Overproduction of uric acid can also be a cause. This can be driven by consuming foods and beverages high in purines, such as red meat, organ meats, certain seafood, and alcohol, particularly beer. Beyond diet, rapid cell turnover from conditions like psoriasis or as a side effect of chemotherapy can also release large amounts of purines, subsequently raising uric acid levels.
Associated Health Conditions
While many individuals with hyperuricemia have no symptoms, the condition is a significant risk factor for several medical problems. The most widely recognized complication is gout, a form of inflammatory arthritis. Gout occurs when excess uric acid in the blood forms sharp, needle-like crystals that deposit in the joints, most commonly affecting the big toe, ankles, or knees. These crystal deposits trigger sudden and severe episodes of pain, swelling, redness, and warmth in the affected joint.
High concentrations of uric acid can also lead to kidney stones. When uric acid levels in the urine become too high, it can precipitate and form these stones, which can cause intense pain and may lead to blockages in the urinary tract. Over a prolonged period, untreated hyperuricemia can also contribute to chronic kidney damage by impairing the kidneys’ filtering ability over time.
A growing body of scientific research has linked high uric acid levels to a greater risk for cardiovascular and metabolic issues. Studies have shown an association between hyperuricemia and conditions like hypertension (high blood pressure), heart disease, and metabolic syndrome. The mechanisms behind these links are an area of active investigation, but it is thought that high uric acid may contribute to endothelial dysfunction, oxidative stress, and inflammation.
Diagnosis and Monitoring
The primary method for diagnosing hyperuricemia is a blood test that measures the serum uric acid level. A healthcare provider will diagnose the condition when uric acid levels are above a certain threshold, generally greater than 7.0 mg/dL for men and 6.0 mg/dL for women. Since many people with high uric acid are asymptomatic, the condition is often discovered during routine blood work or when investigating symptoms of gout or kidney stones.
In some cases, a 24-hour urine collection test may be ordered. This test helps determine whether the high uric acid level is due to the body producing too much of it or not excreting enough through the kidneys.
Once hyperuricemia is diagnosed, regular monitoring is important. Follow-up blood tests are used to track uric acid levels and ensure that management strategies are effective. For individuals without symptoms, monitoring may be the main course of action, with treatment initiated if levels become excessively high or if complications develop.
Management and Treatment Strategies
The initial approach to managing hyperuricemia often involves lifestyle and dietary modifications. Patients are advised to limit their intake of high-purine foods, such as red meat, organ meats, and certain kinds of seafood. Reducing the consumption of alcohol, especially beer, and sugary beverages containing high-fructose corn syrup is also recommended, as these can increase uric acid production or hinder its excretion. Staying well-hydrated by drinking plenty of water helps the kidneys flush uric acid from the body.
Some dietary choices may be beneficial. Research suggests that consuming low-fat dairy products and cherries might help lower uric acid levels. Maintaining a healthy weight through regular physical activity and a balanced diet is also encouraged, as obesity is a risk factor for hyperuricemia.
When lifestyle changes are not enough, or if a patient has experienced complications like gout attacks or kidney stones, medication is often prescribed. There are two main categories of medications used to treat hyperuricemia. The first type, known as xanthine oxidase inhibitors, includes drugs like allopurinol and febuxostat, which work by reducing the body’s production of uric acid.
The second category of medication promotes the excretion of uric acid. Drugs such as probenecid fall into this class, working by helping the kidneys remove uric acid from the body more effectively. The choice of medication depends on the underlying cause of the hyperuricemia—whether it’s overproduction or under-excretion—and the patient’s overall health profile.