Hyperuricemia: Elevated Uric Acid in the Blood

Hyperuricemia is an abnormally high concentration of uric acid in the blood. Common thresholds are above about 7 mg/dL in men and 6 mg/dL in women; clinically it matters most near the saturation point (~6.8 mg/dL) where urate begins to crystallize out of solution. In body fluids uric acid exists mostly as the urate ion. It arises through two broad mechanisms, which can coexist. Overproduction comes from heavy purine turnover (dietary or from cell breakdown) and from fructose metabolism, which both fuels purine synthesis and depletes ATP into uric acid; see Fructose and Uric Acid: Why Sugar Raises Gout Risk. Under-excretion, the more common cause, reflects reduced renal clearance from kidney disease, genetic variants (such as in the SLC2A9 urate-transporter gene), obesity, hypertension, certain medications, and alcohol. Many people with hyperuricemia are asymptomatic and only discover it on a blood test; not everyone with elevated uric acid develops gout. Clinical consequences appear when crystals form in joints, producing Gout: Inflammatory Arthritis from Urate Crystals, or in the urinary tract, producing Uric Acid Kidney Stones. Treatment of symptomatic disease lowers uric acid with allopurinol (reduces production) or uricosuric drugs (increase excretion), but the evidence for treating asymptomatic hyperuricemia is unclear. This is general medical information, not personalized advice.