Kidney Stones

Kidney stones are hard mineral and acid salt deposits that form in the kidneys. They often cause severe pain in the side of your belly or lower back.

In most cases, you'll pass the stone on your own. But you may need surgery to remove your kidney stone if it's too large to pass or at risk of causing an infection.

At the UPMC Kidney Disease Center, we can help. We'll work with you to find a reversible cause of your kidney stones so you can return to your healthy life.

Contact the UPMC Kidney Disease Center

To make an appointment with one of our experts, call 412-802-3043 or book an appointment with one of our kidney disease experts.

What Are Kidney Stones?

A kidney stone is a solid, crystal-like object that forms in a kidney or elsewhere in your urinary tract. It's formed from chemicals in the urine.

Kidney stones can be as small as a grain of sand or larger than a pearl. Based on its size, a kidney stone can be very painful as it passes through the urinary tract.

Types of kidney stones and their causes

The fluid in your pee helps dilute any natural chemical compounds.

Most kidney stones form when urine is too concentrated, causing minerals to stick together — or crystallize — and form a stone.

There are four types of kidney stones:

  • Calcium oxalate is the most common type. They form when oxalate — a naturally compound in some foods — combines with calcium.
  • Uric acid is the next most common type and tends to run in families. They form when purines — compounds in red meat, organ meats, and shellfish — make your pee too acidic. When this happens, stones can form more easily.
  • Struvite is a less common form of kidney stone. It occurs when an infection in the upper part of the urinary tract makes the pee too salty.
  • Cystine is a rare type of stone caused by a genetic disease called cystinuria. It's a lifelong condition and can cause recurring stones.

Kidney stone risk factors and complications

Anyone can get a kidney stone, including children. The National Kidney Foundation notes that about 19% of men and 9% of women will get a kidney stone during their lives.

Dehydration is the biggest risk factor.

In addition, people with these health conditions are at higher risk:

  • Diabetes
  • Gout
  • Heart disease
  • High blood pressure
  • Metabolic syndrome
  • Obesity

If you've had a kidney stone, you have about a 50% risk of getting another one within five years.

Kidney stones also increase your risk for chronic kidney disease.

How to prevent kidney stones

The best ways to reduce your risk of kidney stones are to:

  • Drink plenty of water.
  • Eat more fruits and veggies.
  • Limit sugar-sweetened drinks.
  • Stay at a healthy weight.
  • Get enough calcium in your diet.
  • Eat a low oxalate diet.

If you have regular kidney stones, it can be overwhelming and painful. You have hope at the UPMC Kidney Disease Center.

Kidney Stones Symptoms and Diagnosis

When a stone leaves one of your kidneys, it travels down the ureter — a narrow tube that empties into your bladder.

Very small stones can pass through the ureter and may not cause any symptoms. Large stones cause pain and block the flow of urine.

Symptoms include:

  • Severe kidney pain that can radiate to your upper abdomen, sides, or lower back.
  • Blood in your urine.
  • Nausea or vomiting.
  • Cloudy urine.
  • Fever and chills.
  • Bladder pain.
  • A frequent urge to pee.

Diagnosing kidney stones

To figure out if you have kidney stones, your doctor will first ask about your symptoms and examine you.

Your doctor may also order:

If your doctor thinks you can pass the stone, they might ask you to save it using a special urine strainer. Studying it helps decide the best way to prevent another one.

Your doctor might also ask you to collect your urine over a 24-hour period.

If you often get kidney stones, our expert nephrologists can help. We'll work to find a reversible cause for your kidney stones, so you can get back to your life.

Kidney Stone Treatment

Treatment will keep you comfortable and lessen kidney pain until you're able to pass the stone. Doctors will surgically remove large stones and those that cause an infection.

Nonsurgical treatments for kidney stones

About 80% of very small stones (4 mm or less) will pass on their own. But it can take weeks or months.

You may have kidney pain until it passes, so your doctor might suggest that you:

  • Drink more water.
  • Take a pain reliever.
  • Take medication to reduce the acidity of your pee.
  • Take medicine to help relax the ureter, making it easier to pass the stone.

Surgical treatments for kidney stones

Larger kidney stones and those that cause a blockage or infection may need one of the following surgeries.

Shock wave lithotripsy (SWL)

SWL is a noninvasive, outpatient treatment. High-energy sound waves are directed toward the stone to reduce its size, so it can pass in your urine.

The surgery takes about an hour, plus recovery time.

Your surgeon will use either:

  • Light sedation
  • Local anesthesia
  • General anesthesia

SWL is best for stones located in the kidney. It can remove about 50% of kidney stones within one month, but you may also need further treatments.


Ureteroscopy is usually an outpatient treatment to remove stones from the ureter, near the bladder.

Your surgeon will insert a flexible scope through the bladder and into the ureter. This allows the surgeon to see and remove the stone with the scope.

The procedure takes one to three hours under general anesthesia.

Potential risks of ureteroscopy include:

  • Bleeding
  • Infection
  • Damage to the ureter

Percutaneous nephrolithotomy and nephrolithotripsy

Percutaneous nephrolithotomy and nephrolithotripsy are more invasive surgeries, but they're the most effective at removing kidney stones.

Surgeons use them to remove very large or oddly shaped stones. They're also an option if you're not a candidate for the other procedures.

During the surgery, your surgeon makes a small incision in your back. He or she then removes the stone either through a tube (nephrolithotomy) or crushes it with soundwaves and removes it (nephrolithotripsy).

The procedure itself takes 20 to 45 minutes and requires general anesthesia. You'll stay at the hospital for two to three days and heal at home for about one week.

Potential risks include:

  • Bleeding
  • Infection
  • Injury to nearby organs

Diet changes

The following changes to your diet can help prevent future kidney stones:

  • Drink 8 to 13 cups of water daily. Adding some fresh lemon or lime juice to your water helps make your pee less acidic.
  • Eat less meat and more fruits and veggies to keep your urine less acidic.
  • Limit sugar-sweetened drinks especially those with high fructose corn syrup.
  • Maintain a healthy weight. People with a BMI over 30 kg/m2 are at higher risk of forming stones.
  • Eat less salt by skipping processed, packaged, canned, and fast foods.
  • Avoid high oxalate foods like spinach, beets, rhubarb, wheat bran, nuts, chocolate, and tea.
  • Get enough calcium in your diet. Try to eat two to three calcium-rich dairy foods like Greek yogurt or low-fat milk each day. Leafy green vegetables, tofu, and almonds are good non-dairy sources of calcium. Don't take calcium supplements unless your doctor says you can.

Contrary to popular belief, too much calcium in the diet doesn't cause calcium stones. Calcium from your diet binds oxalate and may reduce your risk of having a future kidney stone.

You should also avoid high doses of vitamin C (>1,000 mg/day), because it forms extra oxalate in your body.

Your UPMC health care team includes registered dietitians who can work with you to structure a diet plan to reduce your risk.