The short answer: High uric acid and kidney disease are closely connected, but the relationship is more complicated than “high uric acid damages the kidneys.” Reduced kidney function can cause uric acid to rise because the kidneys remove less of it. High uric acid may also contribute to problems such as gout and uric acid kidney stones. However, current evidence does not show that lowering uric acid in people who have high uric acid but no symptoms reliably slows CKD progression.
What Is Uric Acid?
Uric acid is a waste product produced when the body breaks down purines, substances found naturally in cells and in some foods and drinks.
The kidneys normally remove much of the body’s uric acid through urine. When kidney function falls, less uric acid may be cleared, so the blood level can increase.
This creates an important two-way relationship:
Reduced kidney function → less uric acid removal → higher uric acid
At the same time, very high uric acid can promote urate crystal formation, which can cause gout and, in some people, kidney stones.
Can High Uric Acid Actually Damage the Kidneys?
Sometimes, but the evidence needs careful interpretation.
Very high uric acid can cause problems when crystals form. Uric acid kidney stones can obstruct urine flow, cause inflammation, and potentially impair kidney function. Recurrent stones or obstruction deserve evaluation.
Gout is another important consequence. Long-standing uncontrolled gout can cause urate deposits in and around joints and, in some cases, kidney-related complications.
However, researchers have also studied whether ordinary asymptomatic hyperuricemia—a high blood uric acid level without gout or stones—directly causes CKD to worsen.
Although observational studies consistently find that higher uric acid is associated with CKD and CKD progression, association does not prove that uric acid is the cause. Uric acid may partly act as a marker of reduced kidney function rather than being the main driver of kidney damage.
Large randomized trials have not shown a clear kidney-protective benefit from lowering uric acid in people with CKD who do not have gout. In the CKD-FIX trial, allopurinol lowered uric acid substantially but did not slow eGFR decline compared with placebo.
Why Does Uric Acid Rise in CKD?
The most important reason is reduced kidney clearance.
Other factors can contribute, including:
- Dehydration
- Obesity and metabolic syndrome
- High alcohol intake
- High intake of certain purine-rich foods
- Sugary drinks and high-fructose products
- Some medications, particularly certain diuretics
- Genetics
- Conditions associated with increased uric acid production or reduced elimination
A high result therefore needs context. It does not automatically mean that uric acid is causing kidney damage.
What Uric Acid Level Is Too High?
There is no single blood uric acid number that proves kidney damage.
A laboratory may flag a result as high based on its own reference range. In gout management, treatment decisions are based on the overall clinical picture rather than simply whether the laboratory marks the number as abnormal.
For example, KDIGO notes that in a person with CKD who has had a first gout episode, uric acid above 9 mg/dL (535 µmol/L) is one factor that may support considering uric-acid-lowering therapy. That is very different from recommending medication for everyone with an elevated uric acid result.
Your result should be interpreted alongside:
- eGFR and creatinine
- Previous uric acid results
- History of gout
- History of kidney stones
- Urine findings
- Medications
- Blood pressure
- Hydration and recent illness
- Other metabolic conditions
One elevated uric acid result does not diagnose kidney disease.
Does Lowering Uric Acid Protect Kidney Function?
This is where an important misconception needs correcting.
Uric-acid-lowering medicines such as allopurinol and febuxostat are effective treatments for appropriate patients with gout. They can reduce urate levels and help prevent gout-related complications.
But they should not automatically be viewed as medicines that prevent CKD from progressing.
KDIGO 2024 recommends against using uric-acid-lowering drugs solely to delay CKD progression in people with CKD and asymptomatic hyperuricemia, because the evidence has not demonstrated a clear kidney benefit.
That does not mean high uric acid should be ignored. It means the reason for treatment matters.
When treatment may be appropriate
Uric-acid-lowering therapy may be considered when someone has clinically important gout, particularly recurrent attacks, tophi, joint damage from gout, or certain higher-risk situations involving CKD.
For people with CKD and symptomatic hyperuricemia, KDIGO prefers xanthine oxidase inhibitors such as allopurinol or febuxostat over uricosuric drugs. Medication choice and dosing require consideration of kidney function and other health conditions.
Do not start, stop, or change these medicines without discussing them with your clinician.
What About Diet?
Diet can influence uric acid, but extreme restriction is usually unnecessary.
Helpful general measures can include:
- Staying adequately hydrated unless you have a medical reason to restrict fluids
- Limiting excessive alcohol intake
- Reducing frequent intake of sugar-sweetened and high-fructose drinks
- Maintaining a healthy weight when appropriate
- Avoiding excessive intake of foods known to trigger gout for you
KDIGO specifically identifies limiting alcohol, meats, and high-fructose corn syrup as dietary measures that may help prevent gout.
If you also have CKD, diabetes, heart failure, kidney stones, or another condition requiring dietary management, your diet should be individualized rather than based on a generic “low-purine kidney diet.”
What Should You Do If Your Uric Acid Is High?
Start by asking why it is high, rather than trying to lower the number as quickly as possible.
A sensible evaluation may include:
- Review the trend. Compare the current uric acid with previous results.
- Check kidney function. Look at creatinine and eGFR rather than uric acid alone.
- Ask about gout or stones. Joint attacks, urate deposits, or previous kidney stones change the significance of the result.
- Review medications. Some drugs, including certain diuretics, can raise uric acid.
- Review other risk factors. Blood pressure, diabetes, weight, alcohol intake, and diet may all matter.
- Avoid unproven “kidney detox” or uric-acid-lowering supplements. Natural products are not automatically safe, particularly when kidney function is reduced.
When Should You Seek Medical Attention?
Seek prompt medical evaluation for symptoms such as:
- Severe flank or back pain with blood in the urine
- Fever with urinary symptoms or suspected kidney infection
- Very low urine output
- Severe vomiting or dehydration
- Sudden severe joint pain and swelling, particularly if this is a first episode
- Symptoms suggesting urinary obstruction
A high uric acid result by itself is generally not an emergency. The urgency depends on the underlying condition and other laboratory or clinical findings.
Bottom Line
High uric acid and kidney disease often occur together, but that does not prove that uric acid is causing CKD.
Reduced kidney function itself commonly raises uric acid. Very high uric acid can cause clinically important problems such as gout and uric acid stones, while evidence that asymptomatic hyperuricemia directly drives CKD progression remains uncertain.
For someone with CKD, the goal should not simply be to make the uric acid number as low as possible. The more useful approach is to look at the eGFR trend, albuminuria, blood pressure, medications, gout or stone history, and overall health, then decide whether uric-acid treatment is actually indicated.