Kidney Stones in Children

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Definition & Facts

What are kidney stones?

Kidney stones are hard, pebble-like pieces of material that form in one or both of a child’s kidneys when high levels of certain minerals occur in urine. Kidney stones rarely cause permanent damage if treated by a health care professional.

Kidney stones vary in size and shape. They may be as small as a grain of sand or as large as a pea. Rarely, some kidney stones are as big as golf balls. Kidney stones may be smooth or jagged and usually are yellow or brown.

A small kidney stone may pass through the urinary tract on its own, causing little or no pain. A larger kidney stone may get stuck along the way. A kidney stone that gets stuck can block the flow of urine, causing severe pain or bleeding. Learn more about the urinary tract and how it works.

A child who has symptoms of kidney stones including severe pain, blood in the urine, or vomiting needs care right away. A health care professional, such as a urologist, can treat any pain and determine how and when to treat the kidney stone. The provider may also prescribe medicine to prevent further problems or treat a urinary tract infection (UTI).

Illustration of a human kidney with several kidney stones blocking the urinary tract.
A small kidney stone may pass through the urinary tract on its own, causing little or no pain. A larger kidney stone may get stuck along the way.

Do kidney stones have another name?

The scientific name for a kidney stone is a renal calculus or nephrolith. You may hear health care professionals call this condition nephrolithiasis, urolithiasis, or urinary stones.

What type of kidney stones occur in children?

Children develop one of four main types of kidney stones, listed below. Treatment for kidney stones usually depends on their size, location, and what they are made of.

Calcium stones

Calcium stones, including calcium oxalate stones and calcium phosphate stones, are the most common types of kidney stones in children. Calcium oxalate stones are more common than calcium phosphate stones.

Calcium from food does not increase the chance of having calcium oxalate stones. Normally, calcium that isn’t taken up by a child’s bones and muscles goes to the kidneys and is flushed out with urine. In some children, the kidneys leak extra calcium, which can join with other waste products to form a kidney stone.

Uric acid stones

A uric acid stone may form when a child’s urine contains too much uric acid. Medical conditions or inherited disorders can cause too much uric acid in your child’s urinary tract. Less often, eating fish, shellfish, and meat—especially organ meats—may increase uric acid in urine and lead to kidney stones.

Struvite stones

Struvite stones may form after an infection in the upper urinary tract, where the kidneys are found. These stones can develop suddenly and become large quickly. Struvite stones tend to affect children whose urinary tracts did not develop normally and the flow of urine may be limited or blocked. Simple urinary tract infections (UTIs), such as bladder infections, don’t usually lead to struvite stones.

Cystine stones

Cystine stones result from a disorder called cystinuria that is passed down through families. In cystinuria, the child’s kidneys leak large amounts of cysteine, an amino acid. Cystine crystals can then form in the urine and cause stones.

How common are kidney stones in children?

Kidney stones are not common in children, but the number of children affected has grown steadily larger during the last several years. Changing eating habits may be responsible, especially the rise in the amount of sodium children eat through processed foods and table salt. Learn how changes in a child’s diet may help prevent kidney stones.

The rise in obesity and less active lifestyles may also cause more children to have kidney stones.

Which children are more likely to develop kidney stones?

Children of all ages can develop kidney stones, including infants, but they occur much more often in teens. A family history of kidney stones makes a child more likely to develop them. Children who’ve had kidney stones in the past have a greater chance of developing another kidney stone.

An unhealthy lifestyle and diet can make children more likely to have kidney stones. For example, drinking too little water or drinking the wrong types of liquid, such as sugary soft drinks or drinks with caffeine, may cause substances in the urine to become too concentrated.

Likewise, too much sodium, a part of salt, may force extra minerals into the urine, which can become kidney stones. Unhealthy amounts of sodium are found in many prepared foods, including restaurant meals, chips, sandwich meats, frozen foods, and some sports drinks.

Children with certain conditions

Children are more likely to develop kidney stones if they have certain conditions, including

  • a blockage in or abnormal shape of the urinary tract
  • chronic, or long-lasting, inflammation of the bowel
  • cystic fibrosis
  • cystic kidney diseases, which are disorders that cause fluid-filled sacs to form on the kidneys
  • cystinuria
  • digestive problems or a history of gastrointestinal tract surgery
  • gout, a disorder that causes painful swelling of the joints
  • hypercalciuria, a condition that runs in families in which urine contains unusually large amounts of calcium; this is the most common condition found in people who form calcium stones
  • hyperoxaluria, a condition in which urine contains unusually large amounts of oxalate
  • hyperparathyroidism, a condition in which the parathyroid glands release too much parathyroid hormone, causing extra calcium in the blood
  • hyperuricosuria, a disorder in which too much uric acid is in the urine
  • obesity
  • repeated urinary tract infections (UTIs)
  • renal tubular acidosis, a disease that occurs when the kidneys fail to remove acids into the urine, which causes a person’s blood to remain too acidic

Children who take certain medicines

Children are more likely to develop kidney stones when taking the following medicines or medicinal diets over a long period of time:

  • diuretics, often called water pills, which help rid the body of water
  • calcium-based antacids
  • too much vitamin D
  • indinavir and other protease inhibitors used to treat HIV infection
  • topiramate and zonisamide, medicines used for seizures and migraine headaches
  • A ketogenic diet, which is used for seizure disorders that do not respond to medicine

What are the complications of kidney stones in children?

Complications of kidney stones are rare if a child is treated by a health care professional before problems occur.

If kidney stones are not treated, they can cause

Symptoms & Causes

What are the symptoms of kidney stones in children?

Symptoms of kidney stones in children include

  • sharp pains in the back, side, lower abdomen, or groin
  • pink, red, or brown blood in the urine, also called hematuria
  • a constant need to urinate
  • pain while urinating
  • inability to urinate or can urinate only a small amount
  • cloudy or bad-smelling urine
  • irritability, especially in young children

A child should see a health care professional right away when any of these symptoms occur. These symptoms can be caused by a kidney stone or a more serious condition.

The pain of a kidney stone may last for a short or long time or may come and go in waves. Along with pain, a child may have

  • nausea
  • vomiting

Other symptoms include

  • fever
  • chills
Teen girl talks to doctor and holds a hand to her lower back.
Pain in the back, side, lower abdomen, or groin can signal a kidney stone in a teenager or child.

What causes kidney stones in children?

Most kidney stones are caused by high levels of calcium, oxalate, or phosphorus in the urine. These minerals are normally found in urine and do not cause problems at normal levels.

Certain foods and beverages may increase the chances of having a kidney stone in children who are more likely to develop them.

When children can’t move for a long time, for example when a child is in a cast after surgery, the chances of developing a kidney stone are higher. When children aren’t moving, their bones may release extra calcium into the blood.

Diagnosis

How do health care professionals diagnose kidney stones in children?

To diagnose kidney stones health care professionals use a child’s

  • a medical history
  • physical exam
  • lab and imaging tests

In addition, a health care provider will ask questions about

  • symptoms
  • family history of kidney stones
  • typical foods and drinks.

What tests do health care professionals use to diagnose kidney stones in children?

Health care professionals may use lab or imaging tests to diagnose kidney stones.

Lab tests

Urine tests can show whether there are high levels of minerals that could form kidney stones. Urine and blood tests can also help determine which type of kidney stone is causing a child’s symptoms.

Urinalysis. A child collects a urine sample at a medical clinic or lab, and a health care professional tests the sample. For an infant or young toddler, a parent may need to use a special urine collection bag. Urinalysis can find blood in the urine and minerals that can form kidney stones. White blood cells and bacteria in the urine can be signs of a urinary tract infection.

24-hour urine collection. This test measures how much urine a child produces, minerals that can form stones, substances that may help prevent stones, and the pH level of the urine. Parents will need to use a urine collection bag for an infant or young toddler. Older children will use a special container.

Blood tests. A health care professional may take a blood sample and send it to a lab to test. The blood test can show high blood levels of certain minerals that can lead to kidney stones in children.

Imaging tests

Imaging tests can help find kidney stones. The tests may also show problems that caused a kidney stone to form, such as a birth defect or blockage in the urinary tract. Children usually do not need anesthesia for imaging tests.

Ultrasound. An ultrasound is often the first choice when a child needs an imaging test to find a kidney stone. An ultrasound uses specialized sound waves to look at structures inside the body without exposing a child to radiation. During an ultrasound test, a child lies on a table while a technician moves a wand called a transducer over the child’s body. Ultrasound can create images of a child’s entire urinary tract. No anesthesia is needed.

Abdominal x-ray. An abdominal x-ray is a picture of the abdomen that uses low levels of radiation and is recorded on film or on a computer. A technician takes an abdominal x-ray at a hospital or outpatient center, and a radiologist reads the images. During the x-ray, a child lies on a table or stands up and the technician positions the machine close to the abdomen. The technician may ask for different positions for additional pictures. Abdominal x-rays can show the location of kidney stones in the urinary tract but not all stones are visible on abdominal x-ray.

Computed tomography (CT) scans. CT scans use a combination of x-rays and computer technology to create images of a child’s urinary tract. CT scans expose children to more radiation than other imaging methods, but they may provide more information. A hospital or radiology center that works with children will know how to adjust a CT scan to use the lowest possible amount of radiation. Your child will lie on a table that slides into a tunnel-shaped device that takes the x-rays. CT scans can show the size and location of a kidney stone, whether the stone is blocking the urinary tract, and conditions that may have caused the kidney stone to form.

CT scans can sometimes be done with a contrast medium, but this is not usually needed to see kidney stones. Contrast medium is a dye or other substance that makes structures inside your body easier to see during imaging tests. If needed, a health care professional may give your child a shot of contrast medium before the CT scan and should explain why the contrast is being given.

Treatment & Prevention

How do health care professionals treat kidney stones in children?

Health care professionals usually treat kidney stones based on their size, location, and type.

Small kidney stones may pass through the urinary tract without treatment. Children may need to urinate through a strainer for a few days to catch the kidney stone in a special container. A health care professional will send the kidney stone to a lab to find out what type it is. Children need to drink plenty of liquid to help move a kidney stone along. A health care professional may also prescribe pain medicine.

Larger kidney stones, or kidney stones that block a child’s urinary tract or cause great pain, may need urgent treatment. A child who is vomiting and dehydrated, may need to go to a hospital and get fluids through an IV.

Kidney stones of varying sizes and shapes.
Health care professionals usually treat kidney stones based on their size and what they are made of.

Kidney stone removal

A urologist can remove the kidney stone or break it into small pieces with the following treatments:

Shock wave lithotripsy. Shock wave lithotripsy works from outside a child’s body to blast the kidney stone into small pieces. The smaller pieces of the kidney stone then pass through the urinary tract. A health care professional gives anesthesia during this outpatient procedure to prevent pain or help a child keep still.

Cystoscopy and ureteroscopy. During cystoscopy, a health care professional uses a thin tube with a tiny lens at one end to look inside the urethra and bladder to find a stone. During ureteroscopy, a longer and thinner instrument is used to see the lining of the ureters and kidneys.

In both procedures, the health care professional inserts the scope through the urethra to see the rest of the urinary tract. Once the stone is found, it can be removed or broken into smaller pieces. The health care professional performs these procedures in the hospital with anesthesia. A child can typically go home the same day.

Percutaneous nephrolithotomy. A thin viewing tool, called a nephroscope, is used to locate and remove the kidney stone. A health care professional inserts the tool directly into the kidney through a small cut made in the back. For larger kidney stones, a laser may be used to break the kidney stones into smaller pieces. A health care professional performs percutaneous nephrolithotomy in a hospital with anesthesia. Recovery usually takes several days in the hospital.

After these procedures, sometimes the urologist leaves a thin flexible tube, called a ureteral stent, in the urinary tract to help urine flow or a stone to pass. Once the kidney stone is removed, it’s sent to a lab to find out what type it is.

After a kidney stone has passed or been removed, a child may need to collect urine for 24 hours. The goal is to measure how much urine is produced in a day, along with mineral levels in the urine. A child is more likely to form stones again if he or she doesn’t make enough urine each day or has high mineral levels.

How can kidney stones in children be prevented?

To help prevent future kidney stones, learn what caused a child’s previous kidney stones. With that information, a health care professional can suggest changes in the child’s eating and drinking habits to prevent future kidney stones.

Drinking liquid

Drinking enough liquid each day is the most important lifestyle habit to help prevent kidney stones. Drinking enough liquid keeps urine diluted and helps flush away minerals that might form stones. Urine should be almost clear if a child is drinking enough water.

A teenager should drink six to eight 8-ounce glasses a day, unless he or she has kidney failure. A teenager who’s had cystine stones may need to drink even more. Younger children can follow their health care professional’s guidance about how much liquid to drink. Talk with a health care professional if a child can’t drink the recommended amount due to other health problems, such as urinary incontinence, urinary frequency, or kidney failure.

The amount of liquid needed also depends on a child's activity level. Children and teenagers who live and exercise in hot weather may need more liquid to replace the fluid lost through sweat. A child may be asked to collect urine over 24 hours to measure the amount produced in a day. If the amount of urine is too low, he or she may need to drink more liquid.

Though water is best, other liquids such as citrus drinks may also help prevent kidney stones. Lemon and lime juice contain very high levels of citrate, which stops crystals from clumping together to form kidney stones. Choose citrus drinks that are low in sugar to avoid taking in excess calories, which can be unhealthy.

Teen girl holds water bottle as she exercises outdoors.
Drinking plenty of liquid helps prevent kidney stones in teenagers and children.

Medicines

After a child has one kidney stone, a health care professional may prescribe medicines to prevent future kidney stones. The medicine may be needed for a few weeks, several months, or longer, depending on what caused the first kidney stone.

For example, for struvite stones, a child may take an antibiotic by mouth for 1 to 6 weeks, or possibly longer. Treatment of an abnormally shaped urinary tract may also be suggested to prevent future struvite stones.

For other types of stones, a health care professional may prescribe a potassium citrate tablet 1 to 3 times daily. A child may continue to take potassium citrate for months or longer, until the risk for kidney stones in gone.

Type of kidney stone Possible medicines prescribed
Calcium Stones
  • potassium citrate, which is used to raise the citrate levels in urine
  • thiazide diuretics, which reduce calcium in the urine
Uric Acid Stones
  • potassium citrate
  • allopurinol, which is used to treat high levels of uric acid in the body
Struvite Stones
  • antibiotics, which are bacteria-fighting medications
Cystine Stones
  • potassium citrate
  • D-penicillamine, which helps dissolve cystine in the urine
  • mercaptopropionyl glycine, which helps dissolve cystine in the urine

Talk with a health care professional about a child’s health history before he or she takes kidney stone medicines. Some kidney stone medicines have minor to serious side effects. Side effects are more likely to occur the longer a child takes the medicine and the higher the dose. Tell the child’s health care professional about any side effects that occur with kidney stone medicine.

Eating, Diet, & Nutrition

Can what children eat or drink help prevent kidney stones?

Drinking enough liquid, mainly water, is the most important lifestyle change a child or teenager can make to prevent kidney stones. A teenager should drink six to eight 8-ounce glasses a day, unless he or she has kidney failure. Younger children can follow their health care professional’s guidance on how much liquid to drink to prevent kidney stones.

Studies have shown that the Dietary Approaches to Stop Hypertension (DASH) diet can reduce the risk of kidney stones. Learn more about the DASH diet.1

Studies have shown that being overweight increases a child’s risk of kidney stones. A dietitian can help plan meals to lose weight.

Does the type of kidney stone affect a child’s food choices?

Yes. If a child has already had kidney stones, ask what type he or she had. Based on the type of kidney stone, changing the amount sodium, animal protein, calcium, or oxalate eaten may help prevent kidney stones.

Specific diets may help with each of these types of kidney stones:

A dietitian who specializes in kidney stone prevention can help plan meals. Find a dietitian who can help.

Calcium Oxalate Stones

Reduce oxalate

Most children who have calcium oxalate stones don't need to limit how much oxalate they take in through food. The best diet depends on the underlying causes of each child's kidney stones. However, when kidney stones are linked to the amount of oxalate eaten, a child may want to avoid these foods to help reduce oxalate in the urine:

  • nuts and nut products
  • peanuts—which are legumes, not nuts, and are high in oxalate
  • rhubarb
  • spinach
  • wheat bran

A health care provider can explain other food sources of oxalate and how much oxalate is safe to eat.

Reduce sodium

The chances of developing kidney stones increase when children eat more sodium. Sodium is a part of salt. Sodium is in many canned, packaged, and fast foods. It is also in many condiments, seasonings, and meats.

Talk with a health care professional about how much sodium is right for children who are trying to avoid kidney stones. See tips to reduce sodium intake.

Limit animal protein

Eating animal protein can make a child more likely to develop kidney stones.

A health care professional may recommend limiting animal protein, including

  • beef, chicken, and pork, especially organ meats
  • eggs
  • fish and shellfish
  • milk, cheese, and other dairy products

Although a child may need to eat less animal protein each day, he or she needs enough protein for good health. Consider replacing some meat and animal protein with beans, dried peas, and lentils, which are plant-based foods that are high in protein and low in oxalate.

Talk with a health care professional about how much total protein a child may need—whether from animal or plant sources—depending on the child’s age, size, and activities.

Get enough calcium from foods

All children need a certain amount of calcium to remain healthy and to keep their bones strong. Talk with a health care professional about how much calcium to consume to prevent getting more calcium oxalate stones. Getting the recommended amount of calcium—from food, not supplements—is important to help prevent another kidney stone from developing. In the right amounts, calcium can block other substances in the digestive tract that may lead to stones.

It may be best to get calcium from low-oxalate, plant-based foods such as calcium-fortified juices, cereals, breads, some kinds of vegetables, and some types of beans. Ask a dietitian or other health care professional which foods are the best sources of calcium.

Calcium Phosphate Stones

Reduce sodium

The chances of developing kidney stones increase when children eat more sodium. Sodium is a part of salt. Sodium is in many canned, packaged, and fast foods. It is also in many condiments, seasonings, and meats.

Talk with a health care professional about how much sodium is right for children who are trying to avoid kidney stones. See tips to reduce sodium intake.

Limit animal protein

Eating animal protein can make a child more likely to develop kidney stones.

A health care professional may recommend limiting animal protein, including

  • beef, chicken, and pork, especially organ meats
  • eggs
  • fish and shellfish
  • milk, cheese, and other dairy products

Although a child may need to eat less animal protein each day, he or she needs enough protein for good health. Consider replacing some meat and animal protein with these plant-based foods that are high in protein:

  • legumes such as beans, dried peas, lentils, and peanuts
  • soy foods, such as soy milk, soy nut butter, and tofu
  • nuts and nut products, such as almonds and almond butter, cashews and cashew butter, walnuts, and pistachios
  • sunflower seeds

Talk with a health care professional about how much total protein a child may need—whether from animal or plant sources—depending on the child’s age, size, and activities.

Get enough calcium from foods

All children need a certain amount of calcium to remain healthy and to keep their bones strong. Talk with a health care professional about how much calcium to consume to prevent getting more calcium phosphate stones. Getting the recommended amount of calcium—from food, not supplements—is important to help prevent another kidney stone from developing. In the right amounts, calcium can block other substances in the digestive tract that may lead to stones.

It may be best to get calcium from plant-based foods such as calcium-fortified juices, cereals, breads, some kinds of vegetables, and some types of beans. Ask a dietitian or other health care professional which foods are the best sources of calcium.

Uric Acid Stones

Limit animal protein

Eating animal protein can make a child more likely to develop kidney stones.

A health care professional may recommend limiting animal protein, including

  • beef, chicken, and pork, especially organ meats
  • eggs
  • fish and shellfish
  • milk, cheese, and other dairy products

Although a child may need to eat less animal protein each day, he or she needs enough protein for good health. Consider replacing some meat and animal protein with these plant-based foods that are high in protein:

  • legumes such as beans, dried peas, lentils, and peanuts
  • soy foods, such as soy milk, soy nut butter, and tofu
  • nuts and nut products, such as almonds and almond butter, cashews and cashew butter, walnuts, and pistachios
  • sunflower seeds

Talk with a health care professional about how much total protein a child may need—whether from animal or plant sources—depending on the child’s age, size, and activities.

Cystine Stones

Drinking enough liquid, mainly water, is the most important lifestyle change children can make to prevent cystine stones. Talk with a health care professional about how much liquid a child may need, depending on the child’s age, size, and activities.

References

Clinical Trials

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support basic and clinical research into many diseases and conditions.

What are clinical trials and what role do children play in research

Clinical trials are research studies involving people of all ages. Clinical trials look at safe and effective new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving quality of life. Research involving children helps scientists

  • identify care that is best for a child
  • find the best dose of medicines
  • find treatments for conditions that only affect children
  • treat conditions that behave differently in children
  • understand how treatment affects a growing child’s body

Find out more about clinical trials and children.

What clinical trials are open?

Clinical trials that are currently open and are recruiting can be viewed at www.ClinicalTrials.gov.

May 2017
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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.

The NIDDK would like to thank:
Michael J.G. Somers, MD; Harvard Medical School; Michelle A. Baum, MD, Harvard Medical School; Jeffrey M. Saland, MD, MSCR, Icahn School of Medicine at Mt. Sinai