Clinical manifestations of hyperuricemia and gout.

Biologically significant hyperuricemia occurs when serum urate levels exceed urate solubility, ie, at approximately 6.8 mg/dL. At serum urate levels above this threshold, manifestations of chronic crystal deposition, including gouty arthritis, may occur, although asymptomatic hyperuricemia often persists for many years without progression. Intercritical asymptomatic periods follow the resolution of acute gout flares, but crystals remain in the joint during these intervals and further deposition may continue silently. Ultimately this may lead to persistent attacks, chronic pain, and, in some patients, joint damage.