[Urate nephrolithiasis. Cause of consequence?].

After World War II the incidence of urolithiasis increased consistently among the general population in this country. Nearly 25% of all examined renal calculi contain uric acid, sodium acid urate or ammonium acid urate as constituents. There are two peaks in lifespan of occurring urate stones: in the adolescence and in the age between 40 and 60 years. The following conditions are due to the formation of uric acid-containing stones: 1. Gout and primary hyperuricemia; 2. secondary hyperuricemia; 3. idiopathic cases with normal renal excretion of uric acid and normouricemia, but with a higher degree of acidity of the urine than normal considering the total renal excretion of acid products; 4. iatrogenic hyperuricemia during insufficient uricosuric therapy. Up to more than 30% of all the patients with recurrent formation of oxalate stones show a clear association with hyperuricemia, hyperuricosuria and increased renal excretion of calcium. In the presence of sodium urate a considerable promotion of precipitation of crystals consisting of calcium oxalate from a meta-stable solution may occur (so-called epitaxy). Frequently the existence of uric acid stones is without any symptoms. Modern views with regard to prophylactic procedures, diet, general and specific medical management including surgical intervention are presented.