Free Urinary Uric Acid (Serum or Plasma Equivalent)
This test measures the amount of uric acid in your urine that is not bound to proteins, helping assess kidney function and potential risk for conditions like gout or kidney stones.
["Uric acid levels can indicate kidney health and metabolic risks."]
Key facts at a glance
- LOINC
- 33411-0
- Short code
- Hgb Free Ur Ql
- Synonyms
- Hgb Free Ur Ql
- Category
- hematology
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms like joint pain (gout), frequent kidney stones, or if they suspect kidney disease. It can also help monitor treatments for conditions affecting uric acid metabolism.
What to Expect Before the Test
No special preparation is needed. You may collect a urine sample at home or provide a blood sample (serum or plasma) during a lab visit. If urine is collected, avoid foods high in purines (e.g., organ meats, shellfish) 24 hours before.
What the Test Results Mean
Higher-than-normal levels may suggest kidney problems, gout, or overproduction of uric acid. Lower levels might indicate kidney issues or medications affecting uric acid. Results are compared to general reference ranges for your age and sex.
Common Conditions Linked to Uric Acid Levels
Elevated free uric acid can be linked to gout, kidney stones, or metabolic syndrome. Low levels may signal kidney dysfunction or certain medications. Always discuss results with your provider for personalized interpretation.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Free Uric Acid in Urine
Frequently asked questions
What causes false high or low results?
How often should I get this test?
Can diet affect this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy