Uric acid is a metabolic waste product. Elevated levels (hyperuricemia) cause gout and kidney stones. The uric acid test is used in evaluating joint pain, kidney stones, and metabolic disorders. Many people have asymptomatic hyperuricemia without complications. This guide covers uric acid testing, normal ranges, and clinical applications.
Reference ranges
- Men: 3.4-7.0 mg/dL
- Women: 2.4-6.0 mg/dL
Hyperuricemia is generally defined as uric acid above 6.8 mg/dL (the saturation point for monosodium urate).
Causes of elevated uric acid
- Genetic predisposition
- High purine diet (red meat, seafood, organ meats)
- Alcohol (especially beer)
- Fructose intake
- Obesity
- Diuretics (especially thiazides)
- Kidney disease (impaired excretion)
- Chemotherapy/cell breakdown
- Dehydration
Gout
Gout occurs when uric acid crystallizes in joints. Acute gout attacks involve sudden severe joint pain, classically the great toe (podagra). Chronic gout can cause tophi and joint damage.
Treatment thresholds:
- Target uric acid below 6.0 mg/dL for most gout patients
- Below 5.0 mg/dL for patients with tophi
Standard treatments include allopurinol, febuxostat, and lifestyle modification. Acute gout treatment differs from long-term urate-lowering therapy.
Asymptomatic hyperuricemia
Many people have elevated uric acid without symptoms. Treatment of asymptomatic hyperuricemia is generally not recommended unless very high levels or specific situations. Lifestyle modification is reasonable.
Kidney stones
Uric acid stones are one type of kidney stone. Persistent hyperuricemia and acidic urine increase risk. Treatment includes urate-lowering and urinary alkalinization.
Frequently Asked Questions
Does high uric acid always cause gout?
No. Many people have hyperuricemia without gout. Genetic factors and other variables determine who develops symptoms.
Should I be treated for asymptomatic hyperuricemia?
Generally no for mild elevation. Very high levels or specific situations may warrant treatment.
What lifestyle changes lower uric acid?
Reduce alcohol (especially beer), limit purine-rich foods (red meat, organ meats, seafood), reduce fructose intake, lose weight, increase water intake.
Do I need to fast for uric acid testing?
Generally no.
How often should uric acid be checked?
For gout patients on therapy: every 3-6 months until target reached, then annually. For asymptomatic patients: not routinely needed.
The bottom line on the uric acid test
Uric acid testing helps diagnose and monitor gout and identify hyperuricemia. Treatment depends on symptoms and complications, not just laboratory values. Lifestyle modification is the foundation; pharmacological treatment for symptomatic disease.