Definition

Kidney stones are crystallized material in the urine. These stones form in the kidneys or other parts of the urinary tract. The kidneys remove waste (in the form of urine) from the body. They also balance the water and salt content in the blood. There are several types of kidney stones:

    
  • The most common type is mostly calcium, along with oxalate or phosphate.
  • Others types contain uric acid, struvite, and/or cystine.

    • Kidney Stone

    Copyright © Nucleus Medical Media, Inc.

    Causes

    Some of the known causes of kidney stones in children include:

        
  • Too much oxalate in the urine
  • Too much calcium in the urine or blood
  • Too much uric acid in the urine
  • Tiny bacteria a stone can form around
  • Inherited abnormality in the way the body handles cystine
  • Foreign bodies in the urinary tract, like stents or catheters
  • Abnormal function of the urinary tract, such as neurogenic bladder

    • Risk Factors

    These factors increase your child’s chance of developing kidney stones:

        
  • Dehydration —not drinking enough fluids
  • Eating foods high in salt
  • Eating a ketogenic diet to help control epilepsy
  • Mineral content of water your child drinks (hardness or softness of the water)
  • Having family members who have had kidney stones or gout
  • Having kidney stones in the past
  • Being overweight
  • Medical conditions (eg, urinary tract infections , metabolic conditions)
  • Geographic location (residents of the Southeast United States have an increased risk)
  • Limited physical activity
  • Foreign material in the urinary tract (eg, catheter)

    • Symptoms

    Occasionally, kidney stones do not cause symptoms, and they leave the body in the urine. The condition can cause severe pain. Symptoms include:

        
  • Sudden, severe pain in the side of the body or mid- or lower back
  • Pain in the belly or groin area
  • Nausea or vomiting
  • Blood in the urine
  • Burning pain when urinating
  • Fever
  • Recurring urinary tract infections

    • Diagnosis

    The doctor will ask about your child’s symptoms and medical history. A physical exam will be done.

    Tests may include:

        
  • Spiral CT scan—a type of x-ray that uses a computer to make pictures of the inside of the kidney
  • KUB (kidney, ureter, bladder)—an x-ray that uses radiation to view the urinary tract
  • Ultrasound —a test that uses sound waves to examine the kidneys
  • Intravenous pyelogram (IVP) —a special x-ray that produces images of the urinary system (less commonly used today)
  • 24-hour urine—a urine test to check levels of many factors, including calcium , phosphorus , uric acid, oxalate, and citrate

    • Treatment

    Treatment depends on the size and location of the kidney stone. Treatment may include:

    Water

    For small kidney stones, having your child drink plenty of water will help her body pass the stone in the urine. The doctor may provide a special cup to catch the stone when it passes so that it can be analyzed. If your child is having a hard time keeping fluids down, she may need to be hospitalized to receive fluids in her vein. The doctor may also give your child pain medicine and antibiotics until the stone passes.

    Surgery

    Surgery may be needed if the stone is:

        
  • Very large or growing larger
  • Causing bleeding or damage to the kidney
  • Causing infection
  • Blocking the flow of urine
  • Unable to pass on its own

    • Types of surgery include:

        
  • Stent placement—used to allow urine to pass
  • Ureteroscopy and stone basketing or laser lithotripsy—camera is used to locate the stone     
  • Stone basketing—A tiny basket is used to remove the stone.
  • Laser lithotripsy—The stone is broken into smaller pieces with a laser if it is too large to remove.
    •     
  • Extracorporeal shock wave lithotripsy (ESWL) —uses shock waves to break up stones that are too large to pass
  • Percutaneous nephrolithotomy—uses a scope placed through a small tube in the back to remove a large stone
  • Lithotomy—open surgery to remove a stone (rarely used now)

    • If your child is diagnosed as having kidney stones, follow the doctor's instructions.

    Prevention

    Once your child has had a kidney stone, he may be more likely to have another. Here are some steps to prevent this condition:

        
  • Have your child drink plenty of fluids, especially water. Avoid sodas.
  • Make sure your child does not eat too much food that is high in salt (eg, potato chips, French fries, processed meats, etc.).
  • A calcium-rich diet (eg, milk and yogurt) is fine, but avoid giving your child too much calcium.
  • If your child is overweight, work with your child’s doctor to learn the safest way for your child to lose weight.