Kidney Stones

What are kidney stones?

Kidney stones are solid masses or crystals that form from substances (like minerals, acids and salts) in your kidneys. They can be as small as a grain of sand or — rarely — larger than a golf ball. Kidney stones are also called renal calculi or nephrolithiasis.

Depending on the size of your kidney stone (or stones), you may not even realize that you have one. Smaller stones can pass through your urinary tract in your pee with no symptoms. Large kidney stones can get trapped in your ureter (the tube that drains urine from your kidney down to your bladder). This can cause pee to back up and limit your kidney’s ability to filter waste from your body. It can also cause bleeding.

It can take as long as three weeks for kidney stones to pass on their own. Even some small stones can cause extreme pain as they go through your urinary tract and out of your body. You may need a provider to break up and remove a stone that can’t pass on its own.

How common are kidney stones?

About 1 in 10 people will get a kidney stone during their lifetime. They’re most common in men in their 30s and 40s. They’re also more common among non-Hispanic white people.

What are the symptoms of kidney stones?

The most common symptom of kidney stones is pain in your lower back, belly or side (flank pain). It might feel like it extends from your groin to your side. It can be a dull pain or sharp and severe. It’s sometimes called colicky pain because it can get worse in waves.

Other kidney stone symptoms include:

• Nausea and vomiting.
• Bloody pee.
• Pain when you pee.
• Inability to pee.
• Feeling the urge to pee a lot.
• Fever or chills.
• Cloudy or foul-smelling pee.

Smaller kidney stones may not cause pain or other symptoms.

What causes kidney stones?

Your pee contains minerals, acids and other substances, like calcium, sodium, oxalate and uric acid. When you have too many particles of these substances in your pee and too little liquid, they can start to stick together, forming crystals or stones. Kidney stones can form over months or years.

Types of kidney stones

Stones are named for the type of crystals they’re made up of:

• Calcium-oxalate and calcium phosphate stones. Calcium-based stones can form when you eat high-oxalate or low-calcium foods and aren’t drinking enough fluids. Calcium-oxalate stones are the most common type of kidney stones.
• Uric acid stones. Eating animal proteins (beef, poultry, pork, eggs and fish) can cause uric acid stones to form.
• Struvite stones. Bacterial infections can cause struvite stones. Repeated infections can lead to a staghorn calculus, a very large kidney stone that usually needs to be surgically removed.
• Cystine stones. An inherited condition called cystinuria causes cystine stones. Cystine is a substance made of two cysteine amino acids bound together.

What are the risk factors for kidney stones?

You might be at a higher risk of developing kidney stones if you:

• Don’t drink enough fluids.
• Eat meat and other protein-rich foods.
• Eat foods high in sodium or sugars (sucrose and fructose).
• Take vitamin C supplements.
• Have a family history of kidney stones.
• Have a blockage in your urinary tract.
• Have had stomach or intestine surgery, including gastric bypass surgery.
• Take certain medications. This includes some diuretics, calcium-based antacids, some antiseizure medications and certain
• Have certain medical conditions.

Medical conditions that increase kidney stone risk

Certain health conditions can put you at a higher risk for kidney stones. These include:

• Cystic fibrosis.
• Cystinuria, a genetic disorder that causes a buildup of cystine.
• Diabetes.
• Gout.
• High blood pressure.
• High calcium levels in your urine (hypercalciuria).
• Inflammatory bowel disease (IBD).
• Kidney cysts.
• Obesity.
• Osteoporosis.
• Parathyroid disease.
• Primary hyperoxaluria.
• Hemiplegia or paraplegia (types of paralysis).

What are the complications of kidney stones?

Kidney stones can put you at risk for:

• A blockage that backs pee up into your kidney, causing it to swell (hydronephrosis).
• Kidney infection (pyelonephritis).
• Acute kidney injury (a type of kidney failure that can be reversible).
• Frequent urinary tract infections (UTIs).
• Chronic kidney disease (CKD).

How are kidney stones diagnosed?

Healthcare providers use imaging, blood and urine (pee) tests to diagnose kidney stones. If your provider suspects you have a kidney stone based on your symptoms and physical exam, you may need one or more of these tests:

• Urine test. A provider can test your pee for blood, stone-forming crystals and signs of infection.
• Imaging. X-rays, CT scans (computed tomography scans) and ultrasound can help your healthcare provider see the size, shape, location and number of stones.
• Blood tests. A provider can use blood tests to check your kidney function, detect infections and look for high levels of calcium or other conditions that could lead to stone formation.

How are kidney stones treated?

If you have a small stone that’s likely to pass on its own, your provider will have you monitor your symptoms until it passes in your pee. They might prescribe medications that keep you comfortable and help the stone pass on its own.

Larger stones need treatment depending on their size, location, whether they’re causing infections or symptoms, and other factors. If you have a large stone or a blockage, or if a stone isn’t passing on its own in a few weeks, your provider will recommend procedures to break up or remove it.

Medications

If you have a kidney stone that can pass on its own and isn’t causing infection, a provider may prescribe or recommend medications to:

• Relax your ureter to help stones pass. Commonly prescribed medicines include tamsulosin (Flomax®) and nifedipine (Adalat® or Procardia®).
• Manage nausea and vomiting.
• Manage pain. Even small stones that can pass on their own can be very painful. Your healthcare provider may prescribe medications or make recommendations for over-the-counter (OTC) medications to manage the pain. Ask your provider before taking ibuprofen. It can increase the risk of kidney failure if you take it during an acute attack of kidney stones — especially if you have underlying health conditions.

Kidney stone procedures

If you have a kidney stone that can’t pass on its own or is blocking your urinary tract, your provider will recommend a procedure to break up and/or remove the stone. The type of procedure they recommend depends on many factors, including the size and location of the stone. Kidney stone procedures include:

• Shockwave lithotripsy. A provider uses shockwaves to break apart the stones from the outside of your body. The fragments can move through your urinary tract and out of your body more easily.
• Ureteroscopy. A provider inserts a scope through your urethra and bladder and into your ureter. Instruments the provider passes through the scope can break up and remove the stone. The smaller pieces can move through your urinary tract and out of your body more easily.
• Percutaneous nephrolithotomy. Your provider may recommend percutaneous nephrolithotomy when they can’t treat a kidney stone with other procedures. During percutaneous nephrolithotomy, your provider inserts a tube directly into your kidney through a tiny incision (cut) in your back. An ultrasound probe breaks apart and removes the stones.
• Laparoscopic surgery. During laparoscopic surgery, your provider makes a small incision to remove the stone. In some rare cases, your provider might need to perform open surgery (with a larger incision) instead of laparoscopy.

Can kidney stones go away on their own?

Yes, around 80% of kidney stones can pass on their own. The amount of time it takes for you to pass a kidney stone depends on its size and location. A stone that’s smaller than 4 mm (millimeters) may pass within one to two weeks. A larger stone could take about two to three weeks to completely pass. Once the stone reaches your bladder, it usually passes in a few days.

If you think you have a kidney stone, make sure a provider evaluates you to check for blockages or other complications. It’s important to follow up with your healthcare provider if you don’t pass the stone within four to six weeks.

Can kidney stones be prevented?

The things you eat and drink can impact your risk for kidney stones. Talk to your healthcare provider or dietitian about ways that you can reduce your risk. They might recommend:

• Drinking plenty of water.
• Limiting animal proteins.
• Limiting foods high in sugar and sodium.
• Limiting foods high in oxalates. If you have calcium oxalate stones, your provider might recommend you avoid foods like spinach, rhubarb, wheat bran, tree nuts and peanuts.
• Maintaining a weight that’s healthy for you.
• Eating foods that are good sources of calcium. While it may not seem like it, foods high in calcium can help prevent kidney stones. The same isn’t true for calcium supplements or antacids with calcium, which can increase your risk for stones.
• Prescription medications. If changes to the things you eat don’t help, your provider may prescribe medications that help prevent kidney stones. The type of medication depends on the type of stones you get.

What can I expect if I have kidney stones?

Around 90% of small kidney stones (smaller than 6 mm) and 60% of large stones (larger than 6 mm) pass on their own. If you have a large kidney stone or one that’s blocking the flow of pee, you’ll need to have a procedure to break up and/or remove it. Sometimes, smaller stones that were expected to pass on their own can grow or move to create a blockage.

If you’ve had kidney stones, you’re likely to get more in the future. You’ll likely need to work on preventing them with changes to the foods you eat and, sometimes, medication.

What is the best way to get rid of kidney stones?

If your provider thinks your kidney stone can pass on its own, you should drink plenty of water to help flush it out. Take any medications as prescribed and follow your provider’s recommendations on what to eat and drink (and what to avoid).

Can I live a normal life with kidney stones?

Kidney stones shouldn’t stop you from going about your daily activities, or drastically reduce your quality of life. Thanks to passing them while you urinate, and thanks to treatment options, kidney stones aren’t permanent.

Do kidney stones cause kidney disease?

If you’ve had kidney stones, you’re at a higher risk for more kidney stones and chronic kidney disease.

Are kidney stones deadly?

No. Kidney stones don’t cause death.

When should I see my healthcare provider?

Don’t hesitate to see your healthcare provider if you’re experiencing symptoms of kidney stones. If you have a kidney stone, you’ll need to know where it’s located and what size it is so that you can get treatment and prevent complications.

When should I go to the emergency department?

Go to the emergency department if the pain is unbearable. You may be prescribed medication for your pain and any nausea/vomiting.

What questions should I ask my healthcare provider?

You may want to ask your provider:

• Do I have a kidney stone or is there another reason for my symptoms?
• What type of kidney stone do I have?
• What size is my kidney stone?
• Where’s my kidney stone located?
• How many kidney stones do I have?
• Do I need treatment or will I be able to pass the kidney stone?
• Should I be tested for kidney disease?
• What changes should I make to my diet?
• What type of procedure should I have to get rid of the stones?