What Causes Kidney Stones?

by | Apr 20, 2021

Learn More About Common Kidney Stone Causes

Kidney stones are hard, mineral-based masses that develop from chemicals in the urine. Once formed, the stone either stays in the kidney or travels down the urinary tract. Sometimes, kidney stones are small and are able to pass on their own naturally. But other times, these stones become lodged in the urinary tract, causing a blockage and immense pain. 

So what causes kidney stones to form? Kidney stones always have underlying causes — some of which are easy to determine and some of which are harder to diagnose. Keep reading to learn more about the most common kidney stone causes, as well as tips to prevent kidney stones in the future.

Types of Kidney Stones

Not all kidney stones are created equally. Knowing what specific type of kidney stone you have will help you and your urologist determine what caused it to form — and how to prevent it in the future. Below are the four main types of kidney stones

Calcium Oxalate Stones

Calcium stones are the most common type of kidney stones. These stones form when urine contains low levels of citrate and high levels of oxalate and calcium. Oxalate is an organic compound found in some plants and food that exits the body through urine. However, this is not a required nutrient and too much of it can lead to kidney stones.

Struvite Stones

Mostly common in women, struvite stones typically form in response to a urinary tract infection. These stones can be large and develop rapidly, causing urinary obstruction and making them very painful. Treating the urinary tract infection can prevent these stones from developing or getting worse.

Uric Acid Stones

Mostly common in men, uric acid stones develop when urine is too acidic. Common causes of uric acid stones include eating a high-protein diet or not drinking enough water. Uric acid stones are also more likely to occur in someone who has gout, a form of arthritis that results in uric acid buildup. 

Cystine Stones

Cystine stones are often caused by a rare genetic disorder called cystinuria. As a result of this condition, excessive amounts of cystine leak into your urine instead of going back into the bloodstream. Kidney stones are more likely to form when there is too much cystine in the urine. Therefore, those with cystinuria are prone to recurring stones. 

Common Kidney Stone Causes

Low Urine Volume

Low urine volume is one of the most common kidney stone causes and it is typically a sign of an underlying issue, such as dehydration. When urine volume is low, urine tends to be more concentrated. As a result, there is less fluid to dissolve the salt in your urine, and your chances of forming kidney stones are much higher. Concentrated urine is dark in color, so making sure your urine is as clear as possible is a good way to tell whether or not you’re staying hydrated.

Related: 3 Changes in Urine and What They Mean

Diet

As is the case with many other conditions, your diet plays a role in your chances of developing a kidney stone. Many kidney stones are caused by eating food that is high in oxalate, sodium, and animal protein. Therefore, limiting the amount of oxalate, sodium, and protein in your diet could help prevent kidney stones from forming.

Additionally, people that consume large quantities of certain dietary supplements may unintentionally put themselves at risk for kidney stones. As always, dietary supplements should only be taken as advised by a doctor, and you should never exceed the recommended quantity.

Related: How Improving Your Diet Helps Your Urological Health

Genetic Factors

As mentioned above, cystinuria is a genetic disorder that causes the body to naturally excrete cystine in overly large quantities. Those with cystinuria, or a family history of this disorder, will be much more prone to developing cystine kidney stones at some point in their lifetime. If you have cystinuria, we recommend being proactive and working with your urologist to develop long-term strategies to prevent kidney stones.

Recurrent Urinary Tract Infections

Fighting infections internally can produce many unintended consequences, including kidney stones. For example, people that regularly develop chronic urinary tract infections are at the highest risk of developing struvite stones. If you have a UTI and also notice symptoms of kidney stones, there’s a good chance you may have developed struvite stones and should contact a urologist as soon as possible. 

Urinary tract infections are typically preventable, so patients should work with their urologist to determine what is causing them to occur. Doing this will help prevent not only a UTI, but also kidney stones from developing. 

Related: Best Treatment Options for UTI 

Obesity

Obesity is characterized as having a body mass index (BMI) over 30 — and is another common cause of kidney stones. In fact, you’re almost twice as likely to develop a kidney stone if you’re obese. This is because obesity may change the acid levels in urine, which increases your risk of kidney stones forming. Similar to recurrent UTIs, we recommend treating the underlying issue, as well as maintaining a healthy diet and lifestyle, in order to prevent kidney stones from developing. 

How to Prevent Kidney Stones

Now that you know about the most common kidney stone causes, it’s time to learn how to prevent them in the first place. Fortunately, kidney stones are relatively common and most doctors have a great deal of experience in treating them. Most people that have struggled with kidney stones are able to prevent them from happening again.

Here are some ways to lower your chances of forming a kidney stone:

  • Drink enough fluids: Staying hydrated is one of the best ways to prevent kidney stones. It is recommended to drink eight to 12 cups of water each day.
  • Eat less oxalate-rich foods: The most common type of kidney stone forms when your body contains too much oxalate. Limit high-oxalate foods, such as spinach, rhubarb, grits, and bran cereal. 
  • Reduce sodium intake: Consuming salt can increase your chances of forming several types of kidney stones, so watch out for salty snacks and other processed foods in your diet. 
  • Avoid eating too much protein: Animal protein produces urine that is more acidic by raising calcium levels and lowering citrate levels in your urine.

See One of Our Urology Specialists

Although uncomfortable, it is possible to pass a mild kidney stone on your own. However, more severe kidney stones will require medication, or in some cases, surgery. As always, contact one of our urology specialists if you are experiencing any symptoms of kidney stones.

Proper nutrition and a healthy lifestyle are crucial when it comes to preventing kidney stones from forming in the future. At Urology Specialists of the Carolinas, we are huge advocates for healthy lifestyles — not only for our patients’ overall well-being, but also for maintaining their urinary tract health. Take the first step towards a healthier you and click below to download our Nutrition and Lifestyle Guide!  

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This content was originally published in September 2014 and was refreshed in April 2021.