Does Diabetes Cause Kidney Stones

High blood sugar can raise your kidney stone risk by up to 60%

Diabetes significantly increases the risk of developing kidney stones, affecting people with type 1 diabetes twice as often and raising the risk by as much as 60% in those with type 2 diabetes. Kidney stones form when minerals and salts in the urine clump together into solid masses, leading to intense pain, urinary problems, and infections.

High blood sugar alters kidney function, making the urine more acidic. This acidic environment encourages the crystallization of uric acid and calcium oxalate. In addition, diabetes disrupts the kidneys' regulation of calcium and hydration, while related factors such as obesity and high blood pressure further increase the likelihood of stone formation.

What Are Kidney Stones?

Kidney stones are hard deposits made of minerals and salts that form inside the kidneys. They can be as small as a grain of sand or grow large enough to fill the kidney's inner structures. Depending on the minerals involved, stones are typically classified as calcium oxalate, uric acid, struvite, or cystine stones. Calcium oxalate and uric acid stones are the most common types seen in people with diabetes.

When a stone is small, it may pass through the urinary tract without causing noticeable symptoms. Larger stones, however, can become lodged in the ureter, the tube that carries urine from the kidney to the bladder, causing significant pain and other complications.

Why Diabetes Raises the Risk of Kidney Stones

Several biological changes linked to diabetes work together to create favorable conditions for stone formation.

Insulin Resistance and Urine Acidity

Insulin resistance, a hallmark of type 2 diabetes, reduces the kidneys' ability to produce ammonia, which normally helps neutralize acids in the urine. As a result, urine becomes more acidic. This acidic environment is ideal for the formation of uric acid stones, since uric acid crystallizes more readily in low-pH urine.

High Blood Sugar and Mineral Imbalance

Chronically elevated blood sugar affects how the kidneys filter and reabsorb minerals such as calcium and oxalate. Over time, this imbalance increases the concentration of stone-forming substances in the urine, raising the likelihood that crystals will form and grow into stones.

Dehydration and Reduced Urine Output

Frequent urination, a common symptom of poorly controlled diabetes, can lead to dehydration if fluid intake does not keep pace with fluid loss. Concentrated urine gives minerals less room to stay dissolved, making crystallization more likely.

Obesity and Related Conditions

Type 2 diabetes is closely linked with obesity and high blood pressure, both of which are independent risk factors for kidney stones. Excess body weight is associated with higher urinary levels of calcium, oxalate, and uric acid, compounding the risk already created by diabetes itself.

Symptoms of Kidney Stones

Not all kidney stones cause symptoms, especially while they remain in the kidney. Once a stone moves into the ureter, however, it can trigger:

Sudden, severe pain in the back, side, lower abdomen, or groin; a burning sensation during urination; blood in the urine; nausea and vomiting; cloudy or foul-smelling urine; and a frequent urge to urinate. People with diabetes should pay close attention to these signs, since diabetes can also raise the risk of urinary tract infections that sometimes accompany kidney stones.

Diagnosing Kidney Stones

Doctors typically diagnose kidney stones through a combination of a physical examination, urine tests, blood tests, and imaging studies such as a CT scan or ultrasound. Urinalysis can reveal crystals, blood, or signs of infection, while imaging confirms the size and location of a stone and helps guide treatment decisions.

Treatment Options

Treatment depends largely on the size of the stone and the severity of symptoms.

Small stones often pass on their own with increased fluid intake and pain management. Larger or more painful stones may require medical intervention, such as shock wave lithotripsy, which uses sound waves to break stones into smaller pieces, or ureteroscopy, a procedure in which a thin scope is used to locate and remove the stone. In more complex cases, surgery may be necessary to remove larger stones directly from the kidney.

For people with diabetes, managing blood sugar levels is also an essential part of both treatment and long-term prevention, since better glycemic control reduces the underlying conditions that promote stone formation.

Preventing Kidney Stones When You Have Diabetes

While diabetes cannot always be separated from stone risk, several strategies can meaningfully lower the chances of developing kidney stones.

Stay Well Hydrated

Drinking enough water throughout the day helps dilute the substances in urine that lead to stone formation. Aiming for pale yellow urine is a simple, practical way to gauge adequate hydration.

Manage Blood Sugar Levels

Keeping blood glucose within target ranges reduces insulin resistance and helps normalize urine acidity, lowering the risk of uric acid stone formation.

Moderate Sodium and Animal Protein Intake

High sodium intake increases calcium excretion in the urine, while excessive animal protein can raise uric acid levels. Reducing processed foods and balancing protein sources can help lower stone risk.

Maintain a Healthy Weight

Because obesity independently raises the risk of kidney stones, gradual, sustainable weight management can help reduce risk factors linked to both diabetes and stone formation.

Monitor Calcium and Oxalate Intake

Contrary to common belief, adequate dietary calcium can actually help prevent calcium oxalate stones by binding oxalate in the digestive tract before it reaches the kidneys. Extremely low-calcium diets are generally not recommended for stone prevention. Limiting foods very high in oxalate, such as spinach and certain nuts, may also be helpful for people prone to this type of stone.

Work Closely With a Healthcare Provider

Because kidney stone risk factors vary from person to person, a healthcare provider or registered dietitian can help tailor prevention strategies based on stone type, diabetes management, and overall health.

When to See a Doctor

Anyone with diabetes who experiences severe pain, blood in the urine, fever, or difficulty urinating should seek medical attention promptly. Early evaluation can prevent complications such as infection or kidney damage, and can also help identify the type of stone involved so that a more targeted prevention plan can be developed.

The connection between diabetes and kidney stones is well established, driven largely by insulin resistance, altered urine chemistry, and related conditions such as obesity and high blood pressure. While the risk is real, it is also manageable. Through consistent blood sugar control, proper hydration, and thoughtful dietary choices, people with diabetes can significantly lower their chances of developing kidney stones and protect their long-term kidney health.

References

National Kidney Foundation: Kidney Stones Overview

Healthline: What's the Connection Between Diabetes and Kidney Stones?

WebMD: Diabetes and Kidney Stones

Kidney International: Diabetes Mellitus and the Risk of Nephrolithiasis

European Urology: Diabetic Severity and Risk of Kidney Stone Disease