Uric Acid Stones

Uric acid stones constitute around 10-20% of kidney stones in the general stone-forming population, but are particularly more prevalent among obese and diabetic kidney stone formers and in patients with gout. The major risk factor predisposing to uric acid stone formation is an overly acidic urine (urinary pH <5.5), while hyperuricosuria and low urine volume are less commonly observed risk factors. Since urine pH is a key determinant of uric acid solubility in urine, uric acid stones can be dissolved with urinary alkalinization. Management of uric acid stones is primarily medical - urinary alkalinization through reduction in dietary acid ash intake and supplementation with potassium citrate or sodium bicarbonate. Urological intervention is generally reserved for cases of severe obstruction, progressive decline in renal function, infection or intractable pain.