High uric acid, clinically called hyperuricemia, happens when your blood levels rise above 6.8 mg/dL. At that point, uric acid can start forming crystals in joints and tissues. The cause is always the same basic imbalance: your body is either making too much uric acid, not getting rid of enough of it, or both.
About two-thirds of the uric acid in your body is produced internally as a byproduct of normal cell turnover. The remaining third comes from the food you eat. On the elimination side, your kidneys handle roughly 70% of uric acid removal, while your intestines take care of the rest. When anything disrupts this production-to-excretion ratio, levels climb.
Your Genes Set the Baseline
Genetics are one of the strongest predictors of high uric acid, and dozens of genes have been identified that influence levels. Most of these genes control urate transporters, the proteins that decide how much uric acid your kidneys reabsorb back into your blood versus how much they flush into your urine. Two genes have the greatest influence. One, called SLC2A9, is active primarily in the kidneys. Certain variants cause it to pull too much uric acid back into the bloodstream instead of releasing it into urine. The other, ABCG2, controls how much uric acid gets released into the gut for removal. Variants that weaken this protein reduce intestinal excretion, leaving more uric acid circulating in the blood.
This is why high uric acid often runs in families, and why some people develop gout despite a relatively healthy diet while others with poor diets never do. Multiple small genetic changes combine to raise or lower your personal set point.
Foods High in Purines
Purines are compounds found in many foods, and when your body breaks them down, the end product is uric acid. The biggest offenders are organ meats (liver, kidneys, sweetbreads, brains, and tripe) and certain seafood, including herring, scallops, mussels, codfish, tuna, trout, and haddock. Red meat and game meats also contribute meaningful amounts.
Vegetables like spinach, asparagus, and mushrooms contain moderate levels of purines, but research has consistently shown they don’t raise uric acid levels the way animal-based purines do. The Cleveland Clinic notes that even higher-purine vegetables haven’t been shown to affect gout symptoms. So the practical concern is animal proteins, not plants.
How Fructose Raises Uric Acid
Sugar, specifically fructose, raises uric acid through a mechanism completely separate from purines. When your liver processes fructose, it uses up energy molecules (ATP) unusually fast. Unlike glucose, which has a built-in feedback system to prevent the liver from burning through too much ATP at once, fructose metabolism has no such brake. The liver phosphorylates fructose as rapidly as it can, which commonly depletes intracellular phosphate. That triggers a chain reaction: the energy byproduct AMP gets broken down into intermediary compounds and ultimately into uric acid, which rises inside liver cells and spills into the bloodstream.
This means sugary drinks, fruit juices, and foods sweetened with high-fructose corn syrup can raise your uric acid even though they contain zero purines. Studies have linked regular soda consumption to significantly higher uric acid levels and increased gout risk.
Alcohol Has a Double Effect
Alcohol raises uric acid from both directions at once: it increases production and blocks excretion. When your body metabolizes ethanol, it produces lactic acid. That lactic acid competes with uric acid for the same excretion pathway in the kidneys, effectively slowing uric acid removal.
Beer is the worst offender. Beyond the ethanol effect, beer is rich in purines and contains compounds called D-amino acids that get metabolized into uric acid through their own pathway, boosting endogenous production. Ethanol in beer also appears to directly inhibit urate transporters in the kidney, further reducing excretion efficiency.
Spirits contain fewer purines than beer, but their high ethanol concentration still promotes enough lactic acid production to competitively block uric acid excretion. Wine appears to have a weaker effect than either beer or spirits, though it’s not risk-free.
Kidney Function and Excretion Problems
Since the kidneys are responsible for about 70% of uric acid removal, any decline in kidney function can cause levels to rise. Chronic kidney disease is one of the most common medical causes of hyperuricemia. As the kidneys lose filtering capacity, uric acid builds up. The intestines partially compensate by increasing their share of excretion, but they can only do so much.
Even without kidney disease, anything that slows uric acid transport in the kidney tubules can cause a backup. Dehydration reduces the volume of fluid flowing through the kidneys and concentrates uric acid. Conditions like metabolic syndrome and insulin resistance also impair renal uric acid clearance, which is one reason high uric acid so often accompanies obesity, high blood pressure, and type 2 diabetes.
Medications That Raise Levels
Several common medications interfere with uric acid excretion. Diuretics (water pills), frequently prescribed for high blood pressure and heart failure, are among the most well-known culprits. Certain types of diuretics make it harder for the kidneys to clear urate, and the resulting rise in uric acid is enough to trigger gout in some people. Low-dose aspirin has a similar effect, reducing kidney excretion at doses typically used for heart protection. Immunosuppressants used after organ transplants, some tuberculosis drugs, and niacin (vitamin B3) at high doses can also elevate levels.
If you’re on one of these medications and your uric acid is climbing, the medication may be a significant contributor, though stopping it without a conversation with your prescriber isn’t the answer since the condition it treats usually matters more.
Body Weight and Cell Turnover
Obesity independently raises uric acid in multiple ways. Larger bodies produce more uric acid simply because there are more cells turning over. Fat tissue, particularly visceral fat around the organs, also increases insulin resistance, which in turn reduces how efficiently the kidneys excrete uric acid. Weight loss reliably lowers uric acid levels, though crash diets and fasting can temporarily spike them because rapid cell breakdown releases a flood of purines all at once.
Conditions that cause rapid cell destruction also raise uric acid dramatically. Cancer treatments that kill large numbers of cells quickly can release so much purine that uric acid spikes to dangerous levels, a situation called tumor lysis syndrome. Blood disorders where the body overproduces and destroys blood cells, like certain leukemias, have the same effect. These are less common causes but explain why uric acid testing sometimes shows up in unexpected medical contexts.
Normal Ranges for Men and Women
Reference ranges differ by sex. For adult men, normal uric acid falls between 4.0 and 8.5 mg/dL. For adult women, the range is 2.7 to 7.3 mg/dL. Women typically have lower levels before menopause because estrogen promotes uric acid excretion through the kidneys. After menopause, levels tend to rise and the gap between men and women narrows.
The clinically meaningful threshold is 6.8 mg/dL, which is the point at which uric acid can begin crystallizing in body tissues at normal body temperature. You can have levels above this threshold for years without symptoms. Not everyone with hyperuricemia develops gout, but the higher the level and the longer it stays elevated, the greater the risk of crystal formation in joints, kidney stones, and potential kidney damage.