Topic Overview

What are kidney stones?

Kidney stones are made of salts and minerals in the urine that stick together to form small "pebbles." They can be as small as grains of sand or as large as golf balls. They may stay in your kidneys or travel out of your body through the urinary tract . The urinary tract is the system that makes urine and carries it out of your body. It is made up of the kidneys, the tubes that connect the kidneys to the bladder (the ureters), the bladder, and the tube that leads from the bladder out of the body (the urethra).

When a stone travels through a ureter, it may cause no pain. Or it may cause great pain and other symptoms.

See pictures of a kidney stone and a stone traveling through a ureter .

What causes kidney stones?

Kidney stones form when a change occurs in the normal balance of water, salts, minerals, and other things found in urine. The most common cause of kidney stones is not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day). Some people are more likely to get kidney stones because of a medical condition or family history.

Kidney stones may also be an inherited disease. If other people in your family have had them, you may have them too.

What are the symptoms?

Kidney stones often cause no pain while they are in the kidneys, but they can cause sudden, severe pain as they travel from the kidneys to the bladder.

Call a doctor right away if you think you have kidney stones. Watch for severe pain in your side, belly, or groin or for urine that looks pink or red. You may also feel sick to your stomach (nausea) and may vomit.

How are kidney stones diagnosed?

You may first find out that you have kidney stones when you see your doctor or go to an emergency room with pain in your belly or side. Your doctor will ask you questions about your pain and lifestyle. He or she will examine you and may do imaging tests such as X-rays to look at your kidneys and urinary tract.

You may need more tests if you have more than one stone or have a family history of stones. To find out the cause of your kidney stones, your doctor may order a blood test and ask you to collect your urine for 24 hours. This can help your doctor find out if you are likely to have more stones in the future.

Kidney stones may not cause any pain. If this is the case, you may learn you have them when your doctor finds them during a test for another disease.

How are they treated?

For most stones, your doctor will suggest drinking enough water to keep your urine clear, or about 8 to 10 glasses of water a day, to help flush the stones out. You may also need to take pain medicine. You can do this at home. Your doctor may give you a medicine to help the stone pass.

If a stone is too large to pass on its own, or if it gets stuck in the urinary tract, you may need more treatment. About 1 or 2 out of every 10 kidney stones needs more than home treatment.¹

The most common medical treatment is extracorporeal shock wave lithotripsy (ESWL). This uses shock waves to break a kidney stone into small pieces. The bits can pass out of your body in your urine. Other times, a doctor will need to remove the stone or place a small flexible plastic tube (called a stent) in the ureter to keep it open while stones pass.

Will I have kidney stones again?

After you have had kidney stones, you are more likely to have them again. You can help prevent them by drinking enough water to keep your urine clear, about 8 to 10 glasses of water a day. You may have to eat less of certain foods. Your doctor may also give you medicine that helps prevent stones from forming.

Frequently Asked Questions

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Cause

Kidney stones may form when the normal balance of water, salts, minerals, and other substances found in urine changes. How this balance changes determines the type of kidney stone you have. Most kidney stones are calcium-type—they form when the calcium levels in your urine change.

Factors that change your urine balance include:

• Not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day). When you don't drink enough water, the salts, minerals, and other substances in the urine can stick together and form a stone. This is the most common cause of kidney stones.
• Medical conditions. Many medical conditions can affect the normal balance and cause stones to form. Gout is one example. Also, people who have inflammatory bowel disease or who have had surgery on their intestines may not absorb fat from their intestines in a normal way. This changes the way the intestines process calcium and other minerals, and it may lead to kidney stones.

More commonly, kidney stones can run in families, as they often occur in family members over several generations.

In rare cases, a person forms kidney stones because the parathyroid glands produce too much of a hormone, which leads to higher calcium levels and possibly calcium kidney stones.

Symptoms

Kidney stones form in the kidney and if they stay in the kidney, they do not typically cause pain. When they travel out of the body through the tubes of the urinary tract (including the ureters, which connect the kidney to the bladder, or the urethra, which leads outside the body), their movement may cause:

• No symptoms, if the stone is small enough.
• Sudden, severe pain that gets worse in waves. Stones may cause intense pain in the back, side, abdomen, groin, or genitals. People who have had a kidney stone often describe the pain as "the worst pain I've ever had."
• Feeling sick to the stomach (nausea) and vomiting.
• Blood in the urine (hematuria), which can occur either with stones that stay in the kidney or with those that travel through the ureters.
• Frequent and painful urination, which may occur when the stone is in the ureter or after the stone has left the bladder and is in the urethra. Painful urination may occur when a urinary tract infection is also present.

Conditions with similar symptoms include appendicitis, hernias, ectopic pregnancy, and prostatitis.

What Happens

A kidney stone begins as a tiny piece of crystal in the kidney. When the urine leaves the kidney, it may carry the crystal out, or the crystal may stay in the kidney. If the crystal stays in the kidney, over time more small crystals join it and form a larger kidney stone.

Most stones leave the kidney and travel through the urinary tract when they are still small enough to pass easily out of the body. No treatment is necessary for these stones. But larger stones may become stuck in the tubes that carry urine from the kidney to the bladder (ureters). This can cause pain and possibly block the urine from flowing to the bladder and out of the body. The pain often becomes worse over 15 to 60 minutes until it is severe. The pain may ease when the stone no longer blocks the flow of urine, and it often goes away when the stone passes into the bladder. Medical treatment is often necessary for larger stones.

• The smaller a stone is, the more likely it is to exit the body (pass) on its own. About 9 out of every 10 stones smaller than 5 mm (0.2 in.) and about 5 out of every 10 stones 5 mm (0.2 in.) to 10 mm (0.4 in.) pass on their own.¹ Only 1 or 2 out of every 10 kidney stones need more than home treatment.¹
• The average time a stone takes to pass ranges between 1 and 3 weeks,¹ and two-thirds of stones that pass on their own pass within 4 weeks of when the symptoms appeared.²
• Almost half of all people who get kidney stones will get more stones within 5 years unless they take preventive measures.³ When you have kidney stones several times over a period of years, the length of time between stones tends to get shorter. It is not possible to predict who will have more stones in the future and who will not.

Problems that may occur with kidney stones include:

• An increased risk of urinary tract infection, or making an existing urinary tract infection worse.
• Kidney damage, if stones block the flow of urine out of both kidneys (or out of one kidney, for people who have a single kidney). For most people with healthy kidneys, kidney stones do not cause serious damage until they completely block the urinary tract for 2 weeks or longer.⁴

Kidney stones are more serious for people who have a single kidney or an impaired immune system or have had a kidney transplant.

Stones in pregnant women

When stones occur during pregnancy, an obstetrician and urologist should determine whether you need treatment. Treatment will depend on your trimester of pregnancy.⁵

Stones in children

Kidney stones are not common in children. When they occur, it is usually between the ages of 8 and 10. Children with kidney stones may also have a urinary tract infection. Often, children with stones also have other medical problems, such as an abnormally developed urinary system, a metabolic disorder, or genetic risks, such as cystic fibrosis.⁶

What Increases Your Risk

Several factors make it more likely you will get kidney stones. Some of these you can control, and others you cannot.

Risk factors you can control

Risk factors for both new and recurring kidney stones that you can control include:

• Fluids you drink.
  • The most common cause of kidney stones is not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day).
  • Drinking grapefruit juice may increase your risk for developing kidney stones.
• Diet. If you think that your diet may be a problem, schedule an appointment with a dietitian and review your food choices.
  • Vitamins C and D can increase your risk of kidney stones when you take more than the daily recommendations. Read supplement labels carefully, and do not take more than the recommended daily doses.
  • Levels of calcium affect your risk of kidney stones. Getting your recommended amounts of calcium combined with a low-sodium, low-protein diet may decrease your risk of kidney stones.⁷ In older people and younger women, one study shows that eating more calcium-rich foods reduces the risk of kidney stones.⁸
  • Diets high in protein, sodium, and oxalate-rich foods, such as dark green vegetables, increase your risk for developing kidney stones.
• Weight and weight gain. Weight gain can result in both insulin resistance and increased calcium in the urine, which can result in a greater risk for kidney stones. In one study, weight gain since early adulthood, a high body mass index (BMI), and a large waist size increased a person's risk for kidney stones.⁹
• Activity level. People who are not very active may have more problems with kidney stones.
• Medicine. Some medicines, such as acetazolamide (Diamox), or indinavir (Crixivan), can cause kidney stones to form.

Risk factors you cannot control

Risk factors for both new and recurring kidney stones that you cannot control include:

• Age and gender.
  • Men between the ages of 30 and 50 are most likely to get kidney stones.³
  • Postmenopausal women with low estrogen levels have an increased risk for developing kidney stones. Women who have had their ovaries removed are also at increased risk.
• A family history of kidney stones.
• A personal history of frequent urinary tract infections.
• Other diseases or conditions, such as inflammatory bowel disease, hyperparathyroidism, cystic fibrosis, gout, or high blood pressure.
• Insulin resistance, which can occur because of diabetes or obesity.
• Prolonged bed rest.
• Bladder problems caused by spinal cord injury.
• Medicines used to control other conditions or diseases, such as antacids or aspirin.
• An abnormal urinary tract, such as the kidneys being joined (horseshoe kidneys).

Risk factors for recurring kidney stones that you cannot control include:¹⁰

• High levels of minerals, such as oxalate, calcium, and uric acid, in the urine.
• Low urine output (stasis).
• Low levels of citrate. Citrate helps prevent stone formation in some people.
• Abnormal urine pH, either very high or very low, over time.

When To Call a Doctor

Call a doctor immediately if you have symptoms that suggest you have a kidney stone, such as:

• Severe pain in your side, abdomen, groin, or genitals. It may get worse in waves.
• Blood in your urine.
• Signs of a urinary tract infection.

Call your doctor if you have been diagnosed with a kidney stone and have another problem, such as:

• Severe nausea or vomiting.
• Fever and chills.
• Severe pain in your side in the area of your kidney (flank pain).

Call your doctor to determine if you need an exam when you:

• Have been diagnosed with a kidney stone, and you need a stronger pain medicine.
• Pass a stone, even if there was little or no pain. Save the stone, and ask your doctor whether it should be tested.

Watchful Waiting

Watchful waiting is a wait-and-see approach. If you get better on your own, you won't need treatment. If you get worse, you and your doctor will decide what to do next.

If you are passing a kidney stone under your doctor's advice, you may be able to pass the stone without medical treatment if you:

• Can control your pain with medicine.
• Know how to look for and collect kidney stones you pass.
• Do not have signs of infection, such as fever and chills.
• Are able to drink plenty of fluids.
• Do not have severe nausea or vomiting.

Who To See

If you need immediate help because of pain from kidney stones, you may see an emergency medicine specialist.

Health professionals who can diagnose and treat nonurgent kidney stones include:

• Family medicine physicians.
• Internists.
• Urologists.
• Nurse practitioners.
• Physician assistants.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

Your first diagnosis of kidney stones often occurs when you see your doctor or go to an emergency room because you are in great pain. Your doctor or an emergency medicine specialist will ask you questions, examine you (medical history and physical exam), test your urine, and may do some imaging tests (such as an ultrasound, X-ray, or CT scan) before suggesting treatment. After you pass a stone, your doctor may give you another exam to find out whether you are likely to get kidney stones again.

Tests to diagnose kidney stones

Your doctor may do any of the following tests to help diagnose kidney stones, see where they are located, and determine whether they are causing or may cause damage to the urinary tract .

• A noncontrast spiral computed tomography (CT) scan is the preferred test for kidney stones. It is a CT scan of the ureters and kidneys, but the scanner moves in a circle as you move through the machine. This test takes half as long as a standard CT scan, provides better images of the kidneys and other organs, and provides different views of the organs.
• An intravenous pyelogram (IVP) is an X-ray test that can show the size, shape, and position of the urinary tract, including the kidneys and ureters. During IVP, a dye called contrast material is injected into a vein (intravenous, IV) in your arm. Then, a series of X-ray pictures is taken at timed intervals. The noncontrast spiral CT replaced this test as the preferred test. See an IVP of a kidney stone .
• A retrograde pyelogram may be done if the IVP or CT scan does not provide a diagnosis. Rather then being injected through your arm, the dye is injected through the tubes that carries urine from the kidneys to the bladder (ureters).
• Urinalysis and urine cultures test your urine. A urinalysis measures several different components of urine, including its acidity (pH) and whether it contains blood. A urine culture tests for a urinary tract infection (UTI).
• An abdominal X-ray (KUB) gives a picture of the kidneys, the tubes that connect the kidneys to the bladder (ureters), and the bladder. It may identify a kidney stone. You may also have this test a few weeks after passing the stone to make sure the entire stone passed (if the stone was originally visible by X-ray).
• An ultrasound exam of the kidneys (ultrasonogram) uses reflected sound waves to produce a picture of the kidneys. It is the preferred test for pregnant women.

Tests to determine what type of kidney stone formed

Determining the type of your kidney stone will help with treatment decisions and measures to prevent stones from forming again. Tests to determine the type of stone include:

• A medical history and physical exam focused on determining your risk for more kidney stones. This includes questions about your diet, lifestyle habits, and medical conditions that may make it easier for stones to form.
• Stone analysis. Your doctor may ask you to collect stones by straining your urine through a fine-mesh strainer or fine gauze. He or she will then determine what type of stone it is.
• Blood chemistry screen, to measure kidney function, levels of calcium, uric acid, phosphorus, electrolytes and other substances that may contribute to stone formation. This test can help your doctor determine your chance of having stones in the future.
• Urine collection for 24 hours, to measure volume, pH, calcium, oxalate, uric acid, and other substances that may contribute to stone formation.

You may not have the above tests. Some doctors do them routinely, and others do them only if they feel you may have more stones in the future. Your doctor generally suggests them if you passed more than one stone and if you have a family history of stones.

Women of childbearing age may get a pregnancy test to make sure that pregnancy is not the cause of symptoms and that it is safe to take X-rays.

Treatment Overview

Your first diagnosis of kidney stones often occurs when you see your doctor or go to an emergency room because you are in great pain. Your doctor may suggest that you wait for the stone to pass and take pain medicine or have a procedure to remove the stone.

Most small stones [less than 5 mm (0.2 in.)] move out of the body (pass) without the need for any treatment other than drinking extra fluids and taking pain medicine.¹

• The smaller a stone is, the more likely it is to pass on its own. About 9 out of every 10 stones smaller than 5 mm (0.2 in.) and about 5 out of every 10 stones 5 mm (0.2 in.) to 10 mm (0.4 in.) pass on their own.¹ Only 1 or 2 out of every 10 kidney stones need more than home treatment.¹
• The average time a stone takes to pass ranges between 1 and 3 weeks,¹ and two-thirds of stones that pass on their own pass within 4 weeks of when the symptoms appeared.²

Not all kidney stones are diagnosed because of immediate symptoms. Your stone may not be causing you pain, and your doctor may find it during a routine exam or an exam for another condition or disease. In this case, you have the same treatment options as noted below.

Treatment for your first stone

If your doctor thinks the stone can pass on its own, and you feel you can deal with the pain, he or she may suggest home treatment, including:

• Drinking more fluids. You need to drink enough water to keep your urine clear, about 8 to 10 glasses a day. Try to drink 2 glasses of water every 2 hours while you are awake. If you have kidney, heart, or liver disease and are on fluid restrictions, talk with your doctor before increasing your fluid intake.
• Not drinking grapefruit juice. Drinking grapefruit juice may increase your risk for developing kidney stones.
• Using pain medicine. Nonprescription medicine, such as nonsteroidal anti-inflammatories (NSAIDs), may relieve your pain. Your doctor can prescribe stronger pain medicine if needed.

Your doctor may prescribe medicine to help your body pass the stone. Calcium channel blockers and alpha-blockers have been shown to help kidney stones pass more quickly with very few side effects.¹¹ Ask your doctor if one of these medicines can help you.

If your pain is too severe, if the stones are blocking the urinary tract , or if you also have an infection, your doctor will probably suggest medical or surgical treatment. Your options are:

• Extracorporeal shock wave lithotripsy (ESWL). ESWL uses shock waves that pass easily through the body but are strong enough to break up a kidney stone. This is the most commonly used medical treatment for kidney stones. See a picture of ESWL .
• Percutaneous nephrolithotomy or nephrolithotripsy. The surgeon puts a narrow telescope into the kidney through a cut in your back. He or she then removes the stone (lithotomy) or breaks it up and removes it (lithotripsy). This procedure may be used if ESWL does not work or if you have a very large stone. See a picture of nephrolithotomy .
• Ureteroscopy. The surgeon passes a very thin telescope tube (ureteroscope) up the urinary tract to the stone's location, where he or she uses instruments to remove the stone or break it up for easier removal. Occasionally, you may need a small hollow tube (ureteral stent) placed in the ureter for a short time to keep it open and drain urine and any stone pieces. Ureteroscopy is often used for stones that have moved from the kidney to the ureter. See a picture of ureteroscopy .
• Open surgery. The surgeon makes a cut in the side or the belly to reach the kidneys and remove the stone. This treatment is rarely used.

Should I use extracorporeal shock wave lithotripsy (ESWL) for my kidney stones?

Preventing future stones

After you have had a kidney stone, you are more likely to have one again. Almost half of all people who have a stone will have more stones within 5 years unless they take preventive measures.³ You may be able to prevent getting more kidney stones by drinking more fluids and making changes in your diet. If you have risk factors for having more stones, such as a family history of stones, your doctor may suggest medicines that help prevent stones from forming.

What To Think About

Your doctor may ask you to collect your urine for 24 hours after you pass a stone so your urine can be tested to find out the type and cause of the stone. Knowing the type of stone can help determine what you can do to avoid having another.

In rare cases, a person forms kidney stones because the parathyroid glands produce too much of a hormone, which leads to higher calcium levels and possibly calcium kidney stones. To help prevent stones from coming back, your doctor may suggest surgery to remove a parathyroid gland or glands (parathyroidectomy).

You may require more treatment for your kidney stones if you have continuing problems and:

• A lot of urinary tract infections.
• Decreased kidney function.
• A single kidney.
• An impaired immune system.
• Have had a kidney transplant.

Prevention

If you have more than one kidney stone, especially if you have a family history of stones, you are more likely to have kidney stones again. But you can take steps to help prevent them:

• Drink more fluids. Try to drink enough water to keep your urine clear, about 8 to 10 glasses of water per day. Slowly increase how much you drink, perhaps adding one more glass of water a day until you are drinking 8 to 10 glasses a day. This slow increase will give your body time to adjust to the extra fluids. You are drinking enough water when your urine is clear or light yellow. If it is dark yellow, you are not drinking enough fluids. If you have kidney, heart, or liver disease and have fluid restrictions, talk with your doctor before increasing how much you drink.
• Change your diet. This may be helpful, but it depends on what is causing your kidney stones. Your doctor may do more tests before deciding whether changing your diet will help reduce your risk of developing another stone. The results of these tests may suggest that it could be helpful to do one or more of the following:
  • Increasing how much fiber you eat. Fiber includes oat bran, beans, whole wheat breads, wheat cereals, cabbage, and carrots.
  • Eating less beef, pork, and poultry.
  • Eating a moderate or high amount of calcium-rich foods, such as dairy products. Getting your recommended amounts of calcium, combined with a diet low in sodium and protein, may decrease your risk of kidney stones.⁷ In older people and younger women, one study indicates that eating more calcium-rich foods reduces the risk of kidney stones.⁸
  • Avoiding foods that are high in oxalate, such as dark green vegetables, nuts, and chocolate.
  • Not adding salt when you cook or eat. Try removing the salt shaker from your table.

For more information on diet and kidney stones, see:

Diet to prevent kidney stones

Medicine

If you get more kidney stones despite drinking more fluids and making changes to your diet, your doctor may give you medicine to help dissolve your stones or to prevent new ones from forming. You may also receive medicine if you have a disease that increases your risk of forming kidney stones. Which medicine you take depends on the type of stone you may have.

Medicine to prevent calcium stones

About 80% of kidney stones are calcium stones.¹ Calcium stones cannot be dissolved by changing your diet or taking medicines. There are medicines that may keep calcium stones from getting bigger or may prevent new calcium stones from forming:

• Thiazides (such as hydrochlorothiazide, chlorthalidone).
• Potassium citrate (Urocit-K).
• Orthophosphate (Neutra-Phos).
• Cholestyramine (Questran).

Medicine to prevent uric acid stones

About 5% to 10% of kidney stones are made of uric acid, a waste product that normally exits the body in the urine.¹ Uric acid stones can sometimes be dissolved with medicine.

• Potassium citrate (Urocit-K).
• Sodium bicarbonate (baking soda).
• Allopurinol (Lopurin, Zyloprim).

Medicine to prevent cystine stones

Less than 1% of kidney stones are made of a chemical called cystine.¹ Cystine stones are more likely to occur in families with a disease that results in too much cystine in the urine (cystinuria).

• Potassium citrate (Urocit-K).
• Penicillamine (Cuprimine, Depen).
• Tiopronin (Thiola).
• Captopril (Capoten).

Medicine to prevent struvite stones

About 10% to 15% of kidney stones are struvite stones.¹ They can also be called infection stones if they occur with kidney or urinary tract infections (UTIs). These types of kidney stones sometimes are also called staghorn calculi if they grow large enough.

• Urease inhibitors (Lithostat).

Home Treatment

Home treatment is often the only thing you need to do when passing a kidney stone. Home treatment includes drinking plenty of fluids, taking pain medicine, and possibly straining and collecting your urine to help determine the type of stone you have.

Drink extra fluids

You need to drink enough water to keep your urine clear, about 8 to 10 glasses of water a day when you are passing a kidney stone.

• Try to drink 2 glasses of water every 2 hours while you are awake. If you have kidney, heart, or liver disease and are on fluid restrictions, talk with your doctor before drinking more fluids.
• Try not to drink grapefruit juice. Drinking grapefruit juice may increase your risk for developing kidney stones.

In some cases, you may need to avoid foods with high levels of oxalate, but your doctor can do tests that show whether this diet will help with your stones.

Use pain medicine

Medicine you can buy without a prescription, such as nonsteroidal anti-inflammatories (NSAIDs), may relieve your pain. NSAIDs include aspirin and ibuprofen (such as Motrin and Advil). Your doctor can prescribe stronger pain medicine if needed.

Collect kidney stones and urine

Your doctor may ask you to collect your kidney stone when it passes so that he or she can examine it to see what caused it to form.

• Your doctor will give you a strainer. Urinate through the strainer and save any stones, including those that look like sand or gravel. Continue to do this for 3 days after your pain stops.
• You can also urinate into a cup or container and empty the container through a strainer to collect the kidney stone. Strainers may be available at your local drugstore. You can also use coffee filters to strain urine.
• Allow the stones to dry, and store them in a plastic or glass container until you can take them to your doctor.

Your doctor may also ask you to collect your urine for 24 hours after you pass a stone, so he or she can check your urine to help determine the type and cause of the stone. Knowing the type of the stone may help you prevent getting stones in the future.

Medications

Medicine you can buy without a prescription, such as nonsteroidal anti-inflammatories (NSAIDs), may relieve your pain. Your doctor can give you stronger pain medicine if needed. NSAIDs include aspirin and ibuprofen (such as Motrin and Advil).

Your doctor may prescribe medicine to help your body pass the stone. Calcium channel blockers and alpha-blockers have been shown to help kidney stones pass more quickly with very few side effects.¹¹ Ask your doctor if one of these medicines can help you.

If you get more kidney stones despite drinking more fluids and making changes to your diet, your doctor may give you medicine to help dissolve your stones or to prevent new ones from forming. You may also receive prescription medicine if you have a disease that increases your risk of forming kidney stones. Which medicine you take depends on the type of stones you have.

Medication Choices

Medicine to prevent calcium stones

About 80% of kidney stones are calcium stones.¹ Calcium stones cannot be dissolved by changing your diet or taking medicines. There are medicines that may keep calcium stones from getting bigger or may prevent new calcium stones from forming:

• Thiazides (such as hydrochlorothiazide, chlorthalidone) and potassium citrate (Urocit-K) are commonly used to prevent calcium stones.
• Orthophosphate (Neutra-Phos) is sometimes used. It has more side effects than thiazides or potassium citrate.

Medicine to prevent uric acid stones

About 5% to 10% of kidney stones are made of uric acid, a waste product that normally exits the body in the urine.¹ Uric acid stones can sometimes be dissolved with medicine.

• Potassium citrate (Urocit-K) and sodium bicarbonate (baking soda) prevent the urine from becoming too acidic, which helps prevent uric acid stones.
• Allopurinol (Lopurin, Zyloprim) makes it more difficult for your body to make uric acid.

Medicine to prevent cystine stones

Less than 1% of kidney stones are made of a chemical called cystine.¹ Cystine stones are more likely to occur in families with a disease that results in too much cystine in the urine (cystinuria).

• Potassium citrate (Urocit-K) prevents the urine from becoming too acidic, which helps prevent cystine kidney stones from forming.
• Penicillamine (Cuprimine, Depen), tiopronin (Thiola), and captopril (Capoten) all help keep cystine dissolved in the urine, which makes cystine-type kidney stones less likely to form.

Medicine to prevent struvite stones

About 10% to 15% of kidney stones are struvite stones.¹ They can also be called infection stones if they occur with kidney or urinary tract infections (UTIs). These types of kidney stones sometimes are also called staghorn calculi if they grow large enough.

• Urease inhibitors (Lithostat) are rarely used because of their side effects and poor results.

What To Think About

If you have uric acid stones or cystine stones and are taking medicine to prevent more stones from forming, you will most likely have to continue taking that medicine for the rest of your life.

Some struvite stones (staghorn calculi) form because of frequent kidney infections. If you have a struvite stone, you will most likely need antibiotics to cure the infection and help prevent new stones from forming, and you will most likely need surgery to remove the stone.

Surgery

People rarely need open surgery to treat kidney stones. In most cases, other less invasive treatments are successful. You may need open surgery when the kidney stone is causing severe bleeding that cannot be controlled. In this case, the surgeon makes a cut in your side or stomach to reach the kidneys, and he or she removes the stone.

Another type of surgery, percutaneous nephrolithotomy or nephrolithotripsy, is also used. The surgeon puts a narrow telescope into your kidney through small cuts in your back. He or she then removes (lithotomy) or breaks up and removes (lithotripsy) the stone. This surgery may be used if other procedures do not work or if you have a very large stone. See a picture of nephrolithotomy .

In rare cases, a person forms kidney stones because the parathyroid glands produce too much of a hormone, which leads to higher calcium levels and possibly calcium-type kidney stones. To help prevent stones from coming back, your doctor may suggest surgery to remove a parathyroid gland or glands (parathyroidectomy).

Other Treatment

If your pain is too great, the kidney stone is blocking the urinary system, or you also have an infection, your doctor will probably suggest medical treatment. Your options are:

• Extracorporeal shock wave lithotripsy (ESWL). This uses shock waves that pass easily through the body but are strong enough to break up a kidney stone. This is the most commonly used medical procedure for treating kidney stones. See a picture of ESWL .
• Ureteroscopy. The surgeon passes a very thin telescope tube (ureteroscope) up the urinary tract to the stone's location, and then he or she uses instruments to remove the stone or break it up for easier removal. Occasionally, you may need a small, hollow tube (ureteral stent) placed in the ureter to keep it open for a short time and drain urine and any stone pieces. This procedure is often used for stones that have moved from the kidney to the ureter. See a picture of ureteroscopy .

The size of the stone, its location in the urinary tract, your overall health, and other factors are all considered in deciding which method to use when breaking up or removing a kidney stone.

Should I use extracorporeal shock wave lithotripsy to treat kidney stones?

Other Places To Get Help

Organization

Related Information

• Chronic Kidney Disease
• Dehydration
• Urinary Tract Infections in Teens and Adults

References

Citations

1. Parmar MS (2004). Kidney stones. BMJ, 328(7453): 1420–1424.

2. Teichman JMH (2004). Acute renal colic from ureteral calculus. New England Journal of Medicine, 350(7): 684–693.

3. Engineer R, Peacock WF IV (2004). Urologic stone disease. In JE Tintinalli et al., eds., Emergency Medicine: A Comprehensive Study Guide, 6th ed., pp. 620–625. New York: McGraw-Hill.

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• Ziyadeh FN, Goldfarb S (2005). Nephrolithiasis. In DC Dale, DD Federman, eds., ACP Medicine, section 10, chap. 12. New York: WebMD.

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