Gout is caused by a buildup of uric acid in the blood, which eventually forms sharp, needle-like crystals in and around joints. When uric acid levels stay above roughly 6.8 mg/dL for a prolonged period, the blood becomes saturated, and crystals of monosodium urate begin depositing in joint tissue. Those crystals trigger an intense inflammatory response that produces the sudden, severe pain of a gout flare.
But high uric acid alone doesn’t guarantee you’ll get gout. Only about 36% of people with elevated levels ever develop a flare, and even among those with very high readings (around 10 mg/dL or above), only about half developed gout over a 15-year follow-up period. What pushes some people from high uric acid into painful gout is a combination of genetics, kidney function, diet, medications, and other health factors.
How Uric Acid Builds Up
Uric acid is a waste product your body creates when it breaks down substances called purines. Purines are part of every cell’s DNA, so your body produces them constantly. Nearly two-thirds of the purines in your body are generated internally, through normal cell turnover and metabolism. The remaining third comes from food. This means that even with a perfect diet, most of your uric acid production is driven by your own biology.
Once produced, uric acid travels through the bloodstream to the kidneys, which are responsible for filtering out more than two-thirds of it. The rest leaves through the gut. Problems on either side of this equation, producing too much uric acid or excreting too little, can tip the balance toward gout. In practice, underexcretion by the kidneys is the more common culprit.
The Role of Your Kidneys
Your kidneys don’t just passively filter uric acid. They actively reabsorb much of it back into the bloodstream through specialized transporter proteins in the kidney tubules. One transporter in particular handles roughly 90% of uric acid reabsorption. When these transporters are overactive, or when the kidney’s ability to secrete uric acid is impaired, less uric acid makes it into urine and more stays in the blood.
Anything that compromises kidney function can worsen this process. Chronic kidney disease, dehydration, and age-related decline in kidney efficiency all reduce your ability to clear uric acid. This is one reason gout becomes more common as people get older.
Genetics and Family History
Several genes directly influence how your body handles uric acid, and inheriting certain variants can substantially raise your risk. Research on three key gene variants found that each one independently roughly doubled the odds of developing gout. When multiple high-risk variants were present together, the effect compounded.
One well-studied gene, ABCG2, encodes a protein that helps move uric acid out of the body through both the kidneys and the gut. A common variant of this gene impairs that function, leading to higher circulating uric acid. Other genes affect the transporter proteins in kidney tubules that control how much uric acid gets reabsorbed versus excreted. If you have a parent or sibling with gout, your own risk is meaningfully higher, and that genetic predisposition can interact with lifestyle factors to amplify the effect.
Foods That Raise Uric Acid
Although diet accounts for only about one-third of your purine intake, certain foods can push uric acid levels high enough to trigger flares. Red meat, organ meats (liver, kidney, sweetbreads), and certain seafood like anchovies, sardines, and shellfish are especially high in purines.
Fructose deserves special attention because it raises uric acid through a different pathway than other foods. When your liver processes fructose, it burns through a key energy molecule (ATP) unusually fast. The byproducts of that rapid breakdown get converted directly into uric acid. This happens quickly: uric acid levels can spike within 30 to 60 minutes of consuming fructose. Sugary drinks, fruit juices, and foods sweetened with high-fructose corn syrup are the biggest sources. This mechanism is distinct from purine-rich foods and helps explain why people who drink a lot of soda have higher gout rates even if they avoid red meat.
Alcohol’s Double Effect
Alcohol raises uric acid in two ways at once: it increases production and decreases excretion through the kidneys. All types of alcohol carry risk, but the pattern varies by drink.
Beer is particularly problematic because it contains purines from the brewing process on top of the alcohol itself. Drinking more than two beers in a 24-hour period raised the risk of a gout flare by 75% compared to not drinking. At four to six beers, the risk jumped to 2.6 times higher. Wine showed a sharp increase at one to two glasses, more than doubling flare risk. Hard liquor followed a similar dose-dependent pattern, with heavy consumption (more than six drinks) nearly tripling the odds of an attack.
Notably, research found that the combination of genetic risk variants and alcohol use had a greater-than-additive effect on gout risk. In other words, if you carry high-risk gene variants, alcohol amplifies your genetic vulnerability more than you’d expect from either factor alone.
Medications That Interfere
Several common medications can raise uric acid as a side effect. Diuretics (water pills), frequently prescribed for high blood pressure and heart failure, are among the most well-known triggers. They cause the kidneys to lose salt and water, which leads to increased reabsorption of uric acid in the kidney tubules. The effect is tied to the degree of fluid loss: the more volume your body loses, the more aggressively the kidneys hold onto uric acid along with other substances.
Low-dose aspirin also reduces uric acid excretion through the kidneys. Immunosuppressant drugs used after organ transplants can have the same effect. If you take any of these medications and notice gout symptoms, it’s worth discussing alternatives with your prescriber rather than simply stopping the medication.
Who Gets Gout
Gout is about three times more common in men than in women globally. This gap exists largely because estrogen helps the kidneys excrete uric acid more efficiently. Before menopause, women have significantly lower uric acid levels than men of the same age. After menopause, that protective effect fades, and women’s gout rates begin to climb.
Risk increases steadily with age in both sexes. Conditions closely linked to gout include obesity, high blood pressure, type 2 diabetes, kidney disease, and metabolic syndrome. These conditions share overlapping mechanisms: insulin resistance, for example, independently reduces the kidneys’ ability to clear uric acid. Carrying excess weight increases purine production from greater cell turnover while also impairing kidney excretion.
From High Uric Acid to a Gout Flare
The progression from elevated uric acid to a gout attack isn’t immediate. Crystals accumulate silently in joint tissue over months or years, a phase sometimes called asymptomatic hyperuricemia. During this time, you feel nothing, but imaging studies can detect crystal deposits long before the first flare.
A flare happens when the immune system suddenly recognizes the crystals as foreign invaders. White blood cells engulf the crystals and activate a powerful inflammatory cascade, releasing signaling molecules that cause rapid swelling, redness, heat, and extreme tenderness. This is why gout attacks come on so abruptly, often overnight. The big toe is the classic location, but gout can strike the ankle, knee, wrist, or fingers.
Flares are often triggered by sudden changes in uric acid levels rather than by a steadily high level. A night of heavy drinking, a large purine-rich meal, dehydration, surgery, or even starting a uric-acid-lowering medication can shift levels enough to destabilize existing crystal deposits and provoke an attack. This is why some people experience their first flare during a period of stress or illness, when multiple factors converge at once.