Hyperuricemia may result from under-excretion or over-production of uric acid. Both may be congenital or acquired. Hyperuricemia may harm the kidney in three ways: by forming renal stones, by blocking tubules and causing acute renal failure, and in those with gout it may contribute to chronic interstitial nephritis. Asymptomatic hyperuricemia of modest degree does not harm the kidneys. Whether or not levels persistently over 10 mg% can do so is open to question, but many physicians consider treatment wise at this point.