What Your Uric Acid Level Means
The 360 threshold, why a normal result during an attack proves nothing, and what else should be checked at the same time.
Part of the Complete Gout Guide.
Key fact: A urate level of 360 micromol/litre or more supports a diagnosis of gout — but the level is often normal or low during an attack. A normal result taken mid-flare does not rule gout out, and NICE advises repeating it at least two weeks after the flare settles.
What the test measures
Serum urate — usually called uric acid on the report — is the amount of urate dissolved in your blood, measured in micromol per litre in the UK. Urate is the end product of purine breakdown, produced constantly by the body and cleared mostly by the kidneys.
Gout happens when urate exceeds the concentration at which it stays dissolved and forms crystals in and around joints. That is why a number matters at all: it is a measure of how close you are to, or past, the saturation point.
The 360 threshold
NICE sets a single clear figure. Measure serum urate in someone with symptoms and signs of gout to confirm the clinical diagnosis, with a level of 360 micromol/litre (6 mg/dL) or more supporting it.
≥360micromol/litre — supports the diagnosis
<360the treatment target once on urate-lowering therapy
<300the lower target with tophi or chronic gouty arthritis
Note that 360 does double duty: it is both the level that supports a diagnosis and the level treatment aims to get you below. That is not a coincidence — it is roughly the point at which urate stays in solution.
Why the level drops during an attack
This is the part that causes the most confusion, and it is worth understanding rather than just remembering.
During an acute flare, urate is being pulled out of the blood and deposited as crystals in the joint, and the inflammatory response itself increases urate excretion. The result is that the blood level can fall into the normal range at exactly the moment you are having the most obvious possible attack of gout.
A normal urate during a flare does not exclude gout. NICE is explicit: if the level is below 360 during a flare and gout is still suspected, repeat the measurement at least two weeks after the flare has settled. People are told "your uric acid is normal, so it isn't gout" far more often than the biochemistry justifies.
The reverse trap matters just as much. A high urate level does not prove that this episode is gout. Plenty of people walk around with a raised urate and no gout at all, and a hot joint in one of them can still be an infection — see gout or septic arthritis.
When to have it done
- Two weeks or more after a flare settles — the most informative time, and the point at which a diagnostic level means what it appears to mean
- Before starting urate-lowering treatment, to establish a baseline
- During titration, to steer the dose — the allopurinol guide covers the schedule
- Annually once stable, alongside kidney function
A level taken in the middle of an attack is not useless — a high result still supports the diagnosis — but a normal one needs repeating rather than believing.
A high level without gout
Raised urate without any attacks is common and has its own name: asymptomatic hyperuricaemia. Most people with a raised level never develop gout.
- It is not treated in itself. Urate-lowering treatment is offered for gout, not for a number on a blood test
- It is worth noticing. A raised urate travels with high blood pressure, kidney impairment, type 2 diabetes and excess weight, so it is often the first thing that prompts a wider check
- It changes what you do with symptoms. If you later get a sudden hot joint, the diagnosis is easier to reach
What else is checked at the same time
| Test | Why it is done alongside urate |
|---|---|
| Kidney function (creatinine and eGFR) | The kidneys clear most urate, so impairment both causes gout and changes which treatments are safe. Chronic kidney disease at stage 3 to 5 is one of NICE's reasons to offer urate-lowering treatment |
| Full blood count and inflammatory markers | To assess how much inflammation there is, and because a raised white count and CRP raise the question of infection |
| HbA1c, lipids, blood pressure | Gout sits within a cluster of cardiovascular and metabolic risk, and a first attack is a reasonable prompt to check the rest |
| Liver function | Relevant before some treatments, and to context alcohol intake |
If a gout diagnosis produces only a urate test and a prescription, something has been missed. The condition is a flag for the rest.
Targets once you are on treatment
The aim of urate-lowering treatment is a number, not an absence of symptoms — which is why it is described as treat-to-target.
- Below 360 micromol/litre for most people
- Below 300 micromol/litre where there are tophi or chronic gouty arthritis, because a lower level dissolves existing deposits faster
- Not "until the attacks stop". Attacks can continue for months after starting treatment while crystals mobilise, which is expected rather than a sign of failure
Dosing and monitoring intervals are covered in the allopurinol guide; what belongs here is the principle that the dose is steered by the number rather than by how you feel.
What moves the number
| Raises urate | Lowers urate |
|---|---|
| Dehydration | Good hydration |
| Alcohol, particularly beer and spirits | Reducing alcohol — see the diet guide |
| Fructose-sweetened drinks | Weight loss, gradually |
| Rapid weight loss, fasting and crash diets | Low-fat dairy |
| Diuretics, low-dose aspirin, ciclosporin and tacrolimus | Urate-lowering medicines such as allopurinol |
| Kidney impairment | — |
Do not stop a prescribed medicine because it raises urate. Diuretics and low-dose aspirin are prescribed for reasons that usually outweigh their effect on urate. Raise it with your prescriber instead — sometimes an alternative exists, and sometimes the right answer is to keep the medicine and treat the gout.
It is also worth being realistic about diet. Dietary change alone rarely moves urate far enough to control established gout, which is why the diet guide frames it as worth doing rather than sufficient on its own.
The test that is definitive
Blood urate supports a diagnosis. It does not prove one. The definitive test is joint aspiration, where fluid drawn from the joint is examined under polarised light: needle-shaped, strongly negatively birefringent urate crystals confirm gout, and the same sample is cultured to exclude infection.
Aspiration is not needed in most straightforward cases, where a classic presentation plus a raised urate is enough. It becomes important when the presentation is atypical, when the joint is unusual, when infection is possible, or when the diagnosis will commit someone to years of treatment and nobody has ever confirmed it. The differential covers what else produces the same picture.
Frequently Asked Questions
What is a normal uric acid level?
In the UK, serum urate is reported in micromol per litre. NICE uses 360 micromol/litre (6 mg/dL) or above as the level that supports a diagnosis of gout, and the same figure is the treatment target once on urate-lowering therapy, with below 300 where there are tophi or chronic gouty arthritis.
Can you have gout with a normal uric acid level?
Yes, and it is common during an attack. Urate is deposited into the joint and excretion increases during a flare, so the blood level can fall into the normal range at the peak of symptoms. NICE advises repeating the measurement at least two weeks after the flare has settled if gout is still suspected.
When should I have my uric acid tested?
The most informative time is at least two weeks after a flare has settled. It is also measured before starting urate-lowering treatment, during dose titration to steer the dose, and at least annually once the dose is stable, usually alongside kidney function.
I have high uric acid but no symptoms. Do I need treatment?
Raised urate without attacks is called asymptomatic hyperuricaemia and is not treated in itself, because most people with a raised level never develop gout. It is worth noting, though, because it travels with high blood pressure, kidney impairment, type 2 diabetes and excess weight.
Does a high uric acid level prove my joint pain is gout?
No. A raised level makes gout more likely but does not confirm that a particular episode is gout, and a hot swollen joint in someone with high urate can still be infected. Joint fluid analysis is the definitive test, distinguishing urate crystals, calcium pyrophosphate crystals and infection.
References
- National Institute for Health and Care Excellence. Gout: diagnosis and management (NG219). nice.org.uk
- NHS. Gout. nhs.uk
- NHS. Septic arthritis. nhs.uk
- British Society for Rheumatology. Management of the hot swollen joint in adults. rheumatology.org.uk
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Gout. cks.nice.org.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. A hot, swollen joint should never be assumed to be gout without assessment, particularly alongside fever or feeling unwell. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.