Definition

Kidney stones are crystallized material in the urine. These stones form in the kidneys or other parts of the urinary tract. Kidney stones may be made up of a variety of minerals in the blood. The most common are calcium, oxalate or phosphate. Others stones may contain uric acid, struvite, and/or cystine.

Kidney Stone

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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. Often a kidney stone can cause severe pain and symptoms such as:

        
  • 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.

    Images of the kidneys and urinary tract may be taken with:

        
  • Spiral CT scan—to make pictures of the inside of the kidney
  • KUB (kidney, ureter, bladder)—an x-ray to view the urinary tract
  • Ultrasound —to examine the kidneys
  • Intravenous pyelogram (IVP) —a special x-ray that produces images of the urinary system (less commonly used today)
  • A 24-hour urine test may also be done to look for levels of minerals in the urine 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.

    Medication

    A kidney stone can be painful as it moves through the urinary tract. The doctor may recommend over-the-counter medications or prescription pain medication.

    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:

        
  • Extracorporeal shock wave lithotripsy (ESWL) —uses shock waves to break up stones that are too large 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.
  •     
  • Percutaneous nephrolithotomy—uses a scope placed through a small tube in the back to remove a large stone (rare)
  • Lithotomy—open surgery to remove a stone (rarely used now)
  • Prevention

    Your child is likely to have another kidney stone if they had one before. Here are some steps that may help to prevent future stones:

        
  • 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 such as potato chips, french fries, processed meats, etc.
  • A calcium-rich diet can help bind oxalate before it reaches the kidney. Encourage milk and yogurt.
  • If your child is overweight, work with your child’s doctor to learn the safest way for your child to lose weight.
  • Encourage water during sporting activities or other active playtimes.