Uric Acid and Gout
The Chemistry Behind Every Flare, Explained Simply
Gout is caused by uric acid (urate) crystals forming in and around a joint. This guide explains what uric acid actually is, why levels rise, what the numbers on a blood test mean, and how that connects to the causes and treatment of gout — without duplicating either.
The Quick Answer
Uric acid (also called urate) is a waste product your body makes when it breaks down cells, plus a smaller amount from food. Everyone has some in their blood. Gout happens when levels stay high enough, for long enough, that urate forms sharp crystals in a joint — which the body then reacts to with sudden pain and swelling.
Having a high uric acid level is not the same thing as having gout, and a normal-looking result doesn't always rule it out either. The number matters, but only alongside your symptoms and your own clinician's assessment.
What It Is
A natural waste product from purines — some made by your own body, some from food.
Where It Comes From
About two-thirds from your own cells breaking down, about a third from diet.
The Target Numbers
NICE guidance targets below 360 µmol/L generally, below 300 µmol/L for some people. See our uric acid levels chart.
Diet's Role
Real, but modest — genetics and kidney clearance matter more for most people.
What Is Uric Acid?
Uric acid — often called urate once it's dissolved in the blood — is a normal waste product. It's made when your body breaks down compounds called purines, which are naturally present in your own cells and in some foods and drinks. Everyone has some circulating in their blood at all times; it only becomes a problem when levels rise too high for too long.
Normally, your kidneys filter the excess out and it leaves the body in urine. Gout develops when that balance tips: urate builds up faster than it's cleared, eventually reaching a concentration where it can no longer stay dissolved and starts forming crystals.
Where It Comes From
Most of the urate in your body isn't from what you ate yesterday. According to Versus Arthritis, roughly two-thirds comes from the ordinary breakdown of purines in your own body's cells, and the remaining third comes from purines in food and drink. That's a big part of why diet changes alone often make only a modest difference — covered in more detail further down this page.
Your Own Body
From the natural turnover of your own cells
Food & Drink
From purines in certain foods and alcohol
Purines break down
From your own cells and from food, purines are constantly broken down into uric acid as part of normal metabolism.
Uric acid enters the blood
It circulates dissolved in the bloodstream, at a level that's usually stable day to day.
Kidneys filter most of it out
In most people, the kidneys clear the excess into urine, keeping blood levels in a normal range.
Why Some People Have High Levels
Given that most urate comes from your own body rather than your diet, it follows that the biggest single factor in high uric acid usually isn't what someone eats — it's how well the kidneys clear it. The British Society for Rheumatology guideline notes that reduced kidney clearance of urate accounts for the underlying problem in more than 90% of people with gout, with the genes you've inherited playing a major part in how efficiently your kidneys manage this.
A smaller number of cases involve the body producing more urate than usual — linked to diet (particularly red meat, some seafood, and alcohol), rare inherited conditions affecting purine metabolism, or other medical conditions. Other things that can raise uric acid or make it harder for the kidneys to clear include being overweight, high blood pressure, high cholesterol, type 2 diabetes, chronic kidney disease, and certain medicines such as diuretics ("water tablets").
- Inherited (genetic) differences in how the kidneys handle urate
- Being overweight or living with obesity
- Chronic kidney disease, high blood pressure, high cholesterol or type 2 diabetes
- Diuretic medicines and some other prescribed drugs
- Regular high alcohol intake, especially beer
- A diet high in purine-rich foods such as red meat and some seafood
If you're wondering why your uric acid is high despite a reasonable diet, kidney clearance and genetics are usually a bigger part of the answer than any single food. Our What Causes Gout guide covers the full picture of risk factors.
How Uric Acid Leads to Gout
Urate can only stay dissolved in the blood up to a certain concentration. Above roughly 360 micromol/litre — the same figure NICE uses as its general treatment target — the blood becomes saturated enough that urate crystals can start to form, typically in and around joints and sometimes in soft tissue. These sharp, needle-like crystals can sit quietly for years, but when the body's immune system reacts to them, the result is the sudden, intense inflammation of a gout flare.
Risk isn't all-or-nothing at any single number. The British Society for Rheumatology guideline, drawing on observational evidence, notes that the risk of a gout attack rises sharply at levels above roughly 500 micromol/litre. That's a general pattern seen across groups of people over time — not a diagnostic cut-off for any one individual. Plenty of people stay well below that level and still develop gout, and plenty of people sit above it for years without a flare. The number is one part of a bigger picture, not a verdict on its own.
High Uric Acid vs. Gout
Having a high uric acid level and having gout are not the same thing. Many people live with elevated urate for years and never develop a single flare — this is sometimes called asymptomatic hyperuricaemia. The British Society for Rheumatology guideline is explicit that it does not recommend treating high urate that isn't causing symptoms.
That's guidance for clinicians, not a blanket rule for every reader in every situation — some people do have other medical reasons for their urate to be monitored or treated even without a flare, and that decision depends on your individual health picture. If you've had a blood test showing high urate but haven't had a diagnosed gout flare, the right next step is a conversation with your own doctor about what it means for you, not a decision made from a general guide like this one.
A single high or normal number doesn't diagnose or rule out gout by itself. High urate without symptoms is different from diagnosed gout, and the two are managed differently — your own doctor is best placed to say which applies to you.
How Uric Acid Is Tested
Uric acid is measured with a simple blood test, and NICE guidance recommends checking it in anyone with symptoms and signs suggesting gout, to help confirm the diagnosis. But timing matters: NICE notes that serum urate can be lower during an acute flare than it usually is, so a normal-looking result taken in the middle of an attack doesn't rule gout out. If the level is below the usual diagnostic threshold but gout is still strongly suspected, NICE recommends repeating the test at least two weeks after the flare has settled, when levels have had a chance to return to their usual baseline.
Where the diagnosis remains uncertain, NICE guidance points to joint aspiration — taking a small fluid sample from the joint and examining it under polarised light microscopy to look for urate crystals directly — the same method used to tell gout apart from similar conditions like pseudogout — as a more definitive test. Imaging such as ultrasound, X-ray or dual-energy CT can also be considered when aspiration isn't possible.
This is a recognised pattern, not a sign that something was done wrong. Your clinician may suggest repeating the test once the flare has settled, or explain what other findings support your diagnosis in the meantime.
Treatment Targets Explained
For people who go on to have urate-lowering treatment, NICE guidance uses a "treat-to-target" approach: rather than a fixed dose, medication is adjusted against regular blood tests until urate reaches a target low enough to let existing crystals gradually dissolve and stop new ones forming. This explains why your doctor might ask for repeat blood tests and adjust your dose over time — it's a normal part of how this treatment works, not a sign anything has gone wrong.
Below 360 µmol/L
(6 mg/dL) — NICE's standard treat-to-target level for most people on urate-lowering therapy.
- Used as the default goal for most people
- Guided by monthly checks while a dose is being adjusted
- Considered for annual monitoring once reached and stable
Below 300 µmol/L
(5 mg/dL) — considered for specific situations, decided with your own clinician.
- For people with tophi or chronic gouty arthritis
- Or ongoing frequent flares despite reaching 360 µmol/L
- Not an automatic target for everyone
This page is about what the numbers mean, not which medicine to take or what dose to use — that's a decision for you and your prescriber. Our Gout Treatment guide covers urate-lowering options like allopurinol and febuxostat in full.
Diet's Real Role
Because roughly two-thirds of the body's urate comes from its own cells rather than food, diet changes alone typically produce a modest reduction in blood levels for most people — helpful, but rarely enough on their own to reach a treatment target once someone needs urate-lowering medicine. Diet is still worth getting right: it can influence flare frequency for some people and supports overall health. It just isn't a substitute for medical treatment when treatment is what's needed, and it doesn't cure gout.
We cover specific food choices in detail elsewhere so this page can stay focused on the uric acid itself — see our dedicated guides on diet, foods to avoid, alcohol and gout, and hydration.
Myths vs Facts
"My urate was high, so it must be gout."
Many people have high urate without ever developing gout. Diagnosis relies on symptoms and, where needed, joint fluid testing — not a blood number alone.
"My level was normal, so it can't be gout."
NICE notes urate can dip during an acute flare. A repeat test a couple of weeks later gives a more reliable picture.
"I must be eating too much red meat or seafood."
About two-thirds comes from your own body's cells. Genetics and kidney clearance drive most cases far more than diet does.
"If it's above normal, I need medicine for it."
Guidelines generally don't recommend treating high urate with no symptoms. Whether that applies to you depends on your wider health picture — ask your doctor.
"My number looked good, so the medicine finished its job."
NICE recommends ongoing annual monitoring for people who continue urate-lowering therapy after reaching target. Decisions about your own medicine are always ones to make with your prescriber, never on your own.
"Which one actually causes gout?"
They're the same substance. "Uric acid" is the compound; "urate" is the form it takes once dissolved in blood. Guidelines and blood tests use the terms interchangeably.
Frequently Asked Questions
What is a normal uric acid level?
Labs vary slightly, but NICE's treatment target for people with gout is below 360 micromol/litre (6 mg/dL). That's a treatment goal rather than a strict cut-off for "normal" in everyone — your own results should be interpreted by your doctor alongside your symptoms.
Can I have high uric acid without having gout?
Yes. Many people have elevated urate for years without ever developing a flare. This is sometimes called asymptomatic hyperuricaemia, and it's managed differently from diagnosed gout.
Does high uric acid always need treatment?
Not automatically. Guidelines generally advise against treating high urate that isn't causing symptoms, though individual circumstances vary. This is a conversation for you and your own doctor, not something to decide from a general guide.
Why was my uric acid normal when I had a flare?
This is a recognised pattern — NICE notes that serum urate can be lower than usual during an acute attack. A repeat test around two weeks after the flare settles usually gives a clearer picture.
What uric acid level is considered high-risk?
Observational data cited in the British Society for Rheumatology guideline shows flare risk rising sharply above roughly 500 micromol/litre. That describes a pattern across groups of people, not a fixed point where gout definitely starts or a level below which you're guaranteed to be safe.
Is gout caused by eating too much red meat or seafood?
Diet is one contributing factor, particularly purine-rich foods and alcohol, but it accounts for only around a third of the body's urate. Genetics and kidney clearance are usually the bigger drivers.
Can losing weight lower my uric acid?
Gradual weight loss can help for some people, since excess weight is linked to higher urate. Crash diets can sometimes temporarily raise urate instead, so a gradual, sensible approach is generally preferred.
What's the difference between uric acid and urate?
They're the same substance in different forms. "Urate" is uric acid once it's dissolved in the bloodstream — the terms are generally used interchangeably in gout guidance.
How is uric acid actually tested for gout?
A blood test measures serum urate. Where the diagnosis is unclear, NICE guidance points to joint fluid aspiration and microscopy to look for urate crystals directly, which is more definitive than a blood level alone.
Can uric acid levels go down without medication?
Lifestyle factors such as gradual weight loss, moderating alcohol, and diet can help some people to a degree, but they don't reliably reach the treat-to-target levels used once medicine is needed. Discuss what's realistic for your situation with your doctor. Our Living With Gout guide covers this long-term picture in more detail.
Does alcohol raise uric acid?
Yes, particularly beer and spirits, and particularly in larger amounts. Our alcohol and gout guide covers this in more detail.
Should I get my uric acid checked regularly if I don't have gout?
That's a decision for you and your GP based on your wider health, not something this page can answer generically. If you have risk factors or a family history, it's a reasonable thing to raise at your next appointment.
This guide explains the general science of uric acid and gout for educational purposes. It is not personal medical advice, cannot interpret your own blood test results, and cannot tell you whether you have or don't have gout. Never start, stop or change a medicine based on this page. Always discuss your own results and treatment with your doctor.