Kidney Stones

What is a kidney stone?

While kidney stones are still relatively uncommon in children, the number of cases is growing. Kidney stones are small, hard deposits of mineral and acid salts formed within the urinary tract, which can obstruct the drainage of urine and may cause intense pain; some children may have nausea and vomiting.

There are many different kinds of stones, with calcium oxalate and calcium phosphate stones being most common. There are other, less common types of kidney stones.

Most of the time, stones are found in the kidney or ureter (the tube that connects the kidney with the bladder). Many stones pass all by themselves, without treatment; others will need to be removed, which can often be done using a noninvasive method.

What are the symptoms of kidney stones?

Symptoms may vary from none, in the case of “silent stones” (stones that are still in the kidney and have not moved to the ureter), to severe pain due to urinary obstruction. Common symptoms of kidney stone disease include:

  • pain in the abdomen, flank (side), back, or groin
  • blood in the urine
  • frequent urination
  • nausea and/or vomiting

Keep in mind that kidney stones affect different children in different ways. Young children in particular may present with vague symptoms that can make diagnosis challenging.

Any child with pain accompanied by blood in the urine — even if it’s just a little bit — should be evaluated by a doctor.

What causes kidney stones?

Kidney stones form when there is too much of the mineral ingredients of the stone and not enough water in the urine.

This can occur either because there is an abnormally high mineral content in the urine, or the urine is too concentrated because of dehydration.

Some rare stone diseases can result from inborn metabolic problems, which means that the child has a genetic condition that causes his body to make these stones. A family history of kidney stones predisposes other members of the family to have stones, although how these tendencies are passed from one generation to the next is not well understood.

Children who can’t move for long periods of time (in traction after surgery, for example) may also be susceptible to stones, because when bones are inactive, they’re unable to regenerate themselves properly, which results in calcium being flushed into the system.

How we care for kidney stones

Boston Children’s has established a pediatric Kidney Stone Program, because more and more children are developing kidney stones. We see children who’ve had kidney stones and those who are at risk for developing them.

Your child will see both a pediatric urologist and a pediatric nephrologist at the same appointment. This multidisciplinary approach allows for direct collaboration between the two specialists to optimize your child’s care and work together to develop a treatment plan — in real time.

We can treat stones in several ways, depending on the size, location, number, and composition of the stones. In nearly all children, we can treat these stones with noninvasive or minimally invasive surgical techniques; in rare instances, we can use robotic surgery techniques to remove the stones.

The best treatment is prevention. Your child will receive a metabolic evaluation to determine if he or she has risk factors for future kidney stones. We then prescribe individualized treatment plans to prevent new stones from forming, and monitor your child with urine and blood tests and sometimes ultrasound exams.