Hyperuricemia is a classic feature of gout, but nearly half of the time gout occurs without hyperuricemia and most people with raised uric acid levels never develop gout.   Thus, the diagnostic utility of measuring uric acid levels is limited.  Hyperuricemia is defined as a plasma urate level greater than 420 μmol/l ( mg/dl) in males and 360 μmol/l ( mg/dl) in females.  Other blood tests commonly performed are white blood cell count , electrolytes , kidney function and erythrocyte sedimentation rate (ESR). However, both the white blood cells and ESR may be elevated due to gout in the absence of infection.   A white blood cell count as high as ×10 9 /l (40,000/mm 3 ) has been documented.