Blood tests for gout
For people who have had gout flares, including those taking or considering medicine to lower uric acid.
6 tests explainedAI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-19
Gout is a form of arthritis caused by uric acid crystals that build up in joints. Uric acid is the main number to follow, and for people on urate-lowering treatment the ACR guideline sets a clear target. Kidney function matters too, because it shapes which medicines fit and how they are started. Some gout medicines also come with their own blood tests before and during treatment.
The tests that matter most
Most important first. Each one links to its full page, where the note for this group sits near the top.
Uric Acid
For people on urate-lowering treatment, the ACR 2020 guideline strongly recommends aiming for a uric acid below 6 mg/dL, with dose changes guided by repeat uric acid tests. Lower levels are linked to fewer flares and faster shrinking of tophi, the swellings under the skin that urate crystals can form.
Sources: American College of Rheumatology (2020) and American College of Rheumatology (2025)
- Men, 18+
- 3.8–8.4 mg/dL
- Women, 18–50
- 2.6–6.2 mg/dL
eGFR (Creatinine-based)
The ACR guideline notes that gout is more likely to progress and form tophi in people with moderate to severe CKD. Kidney function also guides which urate-lowering medicine is preferred and how low the starting dose is.
- Usual adult range
- 60 and above mL/min/1.73 m²
Creatinine
eGFR is worked out from creatinine. The current allopurinol label lists creatinine and eGFR among the tests to check before starting it for gout, and warns that people with kidney disease or kidney stones may be at higher risk of kidney problems on it.
- Men, 15+
- 0.74–1.35 mg/dL
- Women, 16+
- 0.59–1.04 mg/dL
Alanine Aminotransferase (ALT)
The allopurinol label lists liver tests, including ALT, among the tests to check before starting it for gout. It suggests checking liver enzymes from time to time in people who already have liver disease.
- Men, 18+
- 0–44 U/L
- Women, 18+
- 0–32 U/L
G6PD (Glucose-6-Phosphate Dehydrogenase)
Pegloticase is an infused gout medicine. Its FDA label calls for checking people at risk of G6PD deficiency before starting, since that risk is higher with African, Mediterranean or Southern Asian ancestry, and it is not used in people who have the deficiency.
- Usual adult range
- 9.6–16.3 U/g Hb
Urine Uric Acid, 24-Hour
Some people are offered a 24-hour urine uric acid test. The ACR 2020 guideline conditionally recommends against checking urine uric acid when choosing or using medicines that help the kidneys clear urate.
- Usual adult range
- 250–750 mg/24 h
Ranges shown are the usual adult ranges labs print. The range on your own report is the one your result is judged against.
Getting results you can compare
- The ACR/EULAR gout classification criteria, used mainly in research, ideally score a uric acid taken more than 4 weeks after a flare starts and while not on urate-lowering medicine, and suggest retesting under those conditions when practical.
Source: Arthritis & Rheumatology (2015)
- While a urate-lowering dose is being adjusted, the ACR guideline guides each change with repeat uric acid tests, and spreads the changes over weeks to months rather than years.
- On pegloticase, the FDA label calls for a uric acid test before each infusion.
Good to know
- Uric acid can be lower during a gout flare, NICE notes, so a result in the usual range during a flare doesn't settle the question. When gout is still suspected, NICE suggests repeating the test at least 2 weeks after the flare has settled. In one hospital study of 221 people with confirmed gout, about 4 in 10 had a normal level during a flare.
Sources: NICE (2022) and Korean Journal of Internal Medicine (2020)
- The ACR guideline conditionally recommends against starting urate-lowering medicine for a high uric acid without gout symptoms. KDIGO 2024 suggests not using such medicine in people with CKD and no gout symptoms just to slow their kidney disease.
Sources: American College of Rheumatology (2020) and KDIGO (2024)
- Before allopurinol, ACR suggests a genetic test called HLA-B*5801 for people of Southeast Asian descent (such as Han Chinese, Korean or Thai) and for African American people. The gene is linked to a much higher risk of a serious allergic reaction to allopurinol.
Questions you could ask
- What uric acid level are we aiming for, and how often will we check it?
- How does my kidney function affect my gout care?
- When is the best time to recheck my uric acid after a flare?
- Which blood tests make sense before a new gout medicine?
- Is an HLA-B*5801 test relevant for me?
Sources
- 2020 American College of Rheumatology Guideline for the Management of Gout, American College of Rheumatology (2020)
- Gout (patient information), American College of Rheumatology (2025)
- 2015 Gout Classification Criteria: An American College of Rheumatology/European League Against Rheumatism Collaborative Initiative, Arthritis & Rheumatology (2015)
- Clinical features and recurrent attack in gout patients according to serum urate levels during an acute attack, Korean Journal of Internal Medicine (2020)
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease, KDIGO (2024)
- Allopurinol tablets prescribing information, DailyMed (U.S. National Library of Medicine) (2025)
- KRYSTEXXA (pegloticase) injection prescribing information, DailyMed (U.S. National Library of Medicine) (2026)
- Gout: diagnosis and management (NICE guideline NG219), NICE (2022)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-19. How we build and check these pages.
Educational information, not medical advice. Blood Test Tracker doesn’t diagnose or treat, and it doesn’t replace your clinician. Talk with your clinician before changing medications, supplements or care.