Uric Acid

The Uric Acid, serum test (also referred to as UA, trihydroxypurine, or purine‑2,6,8‑trione) is used to assess hyperuricemia and gout and to help differentiate urate overproduction from impaired renal excretion. Results inform interpretation of renal urate handling and support evaluation of renal failure as well as selected metabolic or hematologic disorders. It is employed for baseline and serial monitoring in patients receiving cytotoxic chemotherapy or radiation who are at risk for tumor lysis–associated hyperuricemia, and to track the effectiveness of urate‑lowering therapy.

Uric acid is the final product of purine catabolism derived from nucleic acids. Most purines originate from normal cellular turnover, with a smaller share contributed by diet, including organ meats, red meat, legumes, certain fish, and alcoholic beverages. Following hepatic conversion by xanthine oxidase, uric acid enters the circulation and is handled by the kidneys, where approximately 70% is filtered and excreted amid complex tubular reabsorptive and secretory processes; the remainder is eliminated through the gastrointestinal tract. Hyperuricemia arises from increased production (for example, high cell turnover or tumor lysis) or reduced renal clearance (such as with impaired kidney function). Elevated serum uric acid predisposes to monosodium urate crystal deposition in synovial fluid, causing gouty arthritis, and to urate nephrolithiasis. Serum concentrations may fluctuate during the day and tend to be higher in the morning.