Blood Tests for Gout: Timing, Uric Acid and Kidneys

Gout causes sudden, severe pain in a joint, most often the big toe, with hot, swollen, red skin over it. It happens when uric acid (urate) builds up and forms sharp crystals in and around the joint. Attacks, called flares, typically last 1 to 2 weeks. They can come back, and the NHS says people with frequent attacks or high uric acid may be offered a medicine to lower it.

Blood tests are central to diagnosing and managing gout, but the timing of the test matters and uric acid is only part of the picture. This guide explains when to have a uric acid test, how gout is confirmed, why kidney function and other checks matter, and how blood tests guide treatment. For what a particular uric acid number means, see our guide to uric acid levels.

Test it in Chiswick: our Uric Acid blood test costs £39, with your result explained in person by a practitioner. No GP referral needed. Book this test or call 020 4515 0000. Prefer to test at home? A home finger-prick kit is also available, ask us when you enquire, or see our home kit options.

Quick answer

A uric acid (serum urate) blood test is the main blood test for gout, but timing matters. Levels can fall during a flare, so NICE advises repeating the test at least 2 weeks after the flare settles if gout is still suspected. Finding urate crystals in fluid from the joint confirms the diagnosis. Guidelines also advise checking kidney function and screening for linked conditions such as diabetes and high cholesterol. On urate-lowering treatment, NICE recommends monthly urate tests while the dose is adjusted, aiming for below 360 micromol/L, then yearly checks.

Blood tests that can help

Uric acid: getting the timing right

NICE guideline NG219 uses a serum urate of 360 micromol/L or more to support a diagnosis of gout. During a flare, though, uric acid can drop, sometimes into the normal range. If your level is below 360 micromol/L during a flare and gout is still strongly suspected, NICE advises repeating the test at least 2 weeks after the flare has settled. A raised uric acid without joint symptoms is not gout on its own. Our Uric Acid test costs £39.

Joint fluid: the test that confirms gout

The most certain way to confirm gout is not a blood test. A doctor takes a small sample of fluid from the swollen joint with a thin needle, and the UK Gout Society explains that finding needle-shaped urate crystals under the microscope confirms the diagnosis. NICE suggests this when the diagnosis is uncertain, with imaging such as ultrasound or a dual-energy CT scan as an alternative. Joint fluid testing is also how doctors rule out infection in the joint.

Kidney function

Your kidneys clear most of the uric acid from your body, and NICE lists chronic kidney disease among the conditions linked with gout. Kidney function also affects which urate-lowering medicine is suitable and at what dose, and NICE suggests considering referral to a rheumatologist for people with gout and more advanced kidney disease (CKD stages 3b to 5). Our Kidney Health Check (£49) measures creatinine and eGFR, and the Kidney Health Extended panel (£79) adds cystatin C and uric acid, which makes it useful for monitoring. See kidney function test results explained.

HbA1c, cholesterol and blood pressure

Gout often goes with other conditions. The British Society for Rheumatology guideline says all patients with gout should be screened for cardiovascular risk factors and conditions such as high blood pressure, diabetes, raised cholesterol, obesity, smoking and kidney disease. Our Cholesterol and HbA1c Check (£59) covers the blood test part, and your GP or pharmacist can check your blood pressure. Our guides to HbA1c levels and cholesterol levels explain the results.

Tests that look for other causes

NICE advises that a painful, red, swollen joint is also assessed for septic arthritis, calcium pyrophosphate crystal arthritis (sometimes called pseudogout) and other inflammatory arthritis. If your symptoms do not fit gout neatly, the Rheumatology Check (£79) adds ESR, rheumatoid factor and anti-CCP antibodies to uric acid.

Monitoring on urate-lowering treatment

Urate-lowering medicines such as allopurinol are started at a low dose and increased gradually. NICE recommends checking uric acid monthly to guide each increase, aiming for a level below 360 micromol/L. A lower target of below 300 micromol/L can be considered for people with tophi (lumps of crystals under the skin), chronic gouty arthritis, or frequent flares despite a level below 360. Once the target is reached, NICE suggests yearly monitoring. Read more about treatment options in how to treat gout.

Which test should I book?

• A focused start: Uric Acid, £39. Ideal for checking a level at least 2 weeks after a flare, or for monitoring treatment.
• A broader picture: Rheumatology Check, £79. Uric acid plus ESR, rheumatoid factor and anti-CCP antibodies, useful if it is not clear whether your joint pain is gout or another type of arthritis.
• The fullest view: Omnia Essential Plus, £119. Uric acid with kidney function, HbA1c, glucose, cholesterol and triglycerides, liver markers, a full blood count, CRP, iron studies and a urine test, covering the linked conditions guidelines advise checking.

What blood tests cannot tell you

A blood test cannot prove that a painful joint is gout. Uric acid can be normal during a flare, and many people with a high uric acid never get gout. Blood tests also cannot tell gout apart from an infected joint or from calcium pyrophosphate crystals, which is why a doctor may need to examine the joint and test the fluid. If the picture is unclear, the NHS says you may be referred to a rheumatologist, who may test fluid from the joint or arrange a scan.

When to see a GP urgently

A hot, swollen joint with a fever can be septic arthritis, an infection inside the joint that needs urgent treatment. Ask for an urgent GP appointment or call NHS 111 if:

• you have sudden joint pain and swelling and the pain is getting worse, you have a very high temperature, or you feel sick or cannot eat
• you have pain in a joint and feel generally unwell, hot, cold or shivery
• you find it difficult to move a joint, or the skin over it is hot, swollen or has changed colour

See a GP (non-urgently) if you have gout symptoms for the first time or your usual treatment is not working.

Frequently asked questions

Should I have a uric acid test during a gout attack?

You can, and a high result supports the diagnosis. But levels can fall during a flare, so if the result is below 360 micromol/L and gout is still suspected, NICE advises repeating the test at least 2 weeks after the flare settles.

Can you have gout with a normal uric acid level?

Yes, particularly during a flare. A normal result taken during an attack does not rule gout out, which is why the repeat test is timed for after the flare.

How often should uric acid be checked on allopurinol?

NICE recommends monthly checks while the dose is being increased, until you reach your target, then considering a yearly check after that. Your GP may also check kidney function during this time.

Why does kidney function matter in gout?

The kidneys remove most uric acid, so reduced kidney function can raise it. Kidney function also affects which medicines and doses are safe for you.

Does high uric acid mean I have gout?

No. Many people with raised uric acid never have a gout attack. Gout is diagnosed from typical symptoms, ideally with crystals seen in joint fluid. Our guide to what causes gout explains why some people develop it.

Gout blood tests in Chiswick

Omnia Lifestyle is at 8 to 9 Bedford Corner, The Avenue, Chiswick, London W4 1LZ, a short walk from Turnham Green station (District line; Piccadilly line trains stop there early morning and late evening only) and served by buses 94, E3 and 272. Limited parking is available on request when you book. Every clinic test price includes your sample taken at the clinic, analysis at the Randox accredited laboratory, a practitioner review of your result with you, and a GP feedback report on request. You do not need a GP referral, and most results are back within a few working days.

Useful links: book a Uric Acid test or the Omnia Essential Plus panel, or compare every blood test and price. Our guides to uric acid levels and how to treat gout go into more detail. If you would like support alongside your GP care, see our gout care at Omnia.

This article is general information, not medical advice. Discuss your results with your GP or practitioner.