Normal Uric Acid Levels
Normal serum uric acid levels are approximately 7 mg/dL or less for men and postmenopausal women, and 6 mg/dL or less for premenopausal women, though optimal levels for preventing uric acid-related complications may be lower at <6 mg/dL for all individuals. 1, 2
Laboratory-Defined Reference Ranges
Most clinical laboratories establish their own reference ranges by calculating the mean plus two standard deviations from their local healthy population, with separate calculations for men and women. 2 This laboratory-specific approach can increase the likelihood ratio for detecting true hyperuricemia up to 9.74 (95% CI, 7.45 to 12.72). 2 Always verify the specific reference range provided by the laboratory performing your patient's test, as these values can vary between institutions. 2
Gender-Specific Normal Values
Traditional Reference Ranges
- Men and postmenopausal women: Upper limit of normal is approximately 7 mg/dL 1
- Premenopausal women: Upper limit of normal is approximately 6 mg/dL 1
- Men consistently demonstrate higher serum uric acid levels than women, which is why gender-specific reference ranges are essential 2
Alternative Normal Ranges from Research
Some studies suggest slightly different ranges based on healthy populations:
- Men: 3.5-7.2 mg/dL 3
- Premenopausal women: 2.6-6.0 mg/dL 3
- Males (Thai population study): 6.0-6.4 mg/dL 4
- Females (Thai population study): 4.6-4.8 mg/dL 4
Optimal Target Levels for Disease Prevention
Emerging evidence suggests that a threshold value <6.0 mg/dL may better identify truly healthy subjects and prevent uric acid-related complications beyond gout. 3 This lower target is supported by several considerations:
- Levels above 6 mg/dL are associated with significantly increased gout risk—over 4 times higher in men and 17 times higher in women compared to those below this threshold 2
- Silent deposition of monosodium urate crystals can occur at levels traditionally considered "normal," leading to early destructive skeletal changes 3
- Treatment guidelines for gout recommend achieving serum uric acid levels of 6 mg/dL or less 1
- Some experts suggest targeting serum uric acid between 5.0-6.0 mg/dL as reasonable to balance efficacy and safety 5
Critical Clinical Caveats
Normal Levels Do Not Exclude Gout
Serum uric acid levels do not confirm or exclude gout, as many people with hyperuricemia never develop gout, and during acute attacks serum levels may be normal. 6 This occurs because:
- Uric acid behaves as a negative acute phase reactant, temporarily decreasing during episodes of acute inflammation and stress 2
- Levels can fluctuate during acute gout attacks, sometimes falling to normal or near-normal ranges 2
Elevated Levels Do Not Confirm Gout
Conversely, hyperuricemia alone does not necessarily indicate gout, as many individuals with elevated uric acid never develop symptomatic disease. 6, 2
Factors Affecting Uric Acid Levels
Interpretation must account for:
- Diet: Purine-rich foods can elevate levels 2
- Medications: Diuretics commonly increase uric acid 2
- Renal function: Impaired kidney function reduces uric acid excretion 2
When to Check Renal Uric Acid Excretion
Measure 24-hour urinary uric acid excretion in selected patients with family history of young-onset gout, gout onset before age 25, or history of renal calculi. 6 Normal 24-hour urinary uric acid ranges:
Systemic Implications of Elevated Uric Acid
Hyperuricemia should be recognized as a red flag for metabolic syndrome and cardiovascular disease, even in the absence of gout. 7 Elevated levels are associated with: