Kidney Stones

What is a kidney stone?

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. While kidney stones are still relatively uncommon in children, the number of cases is growing.

There are many different kinds of stones. The most common types are:

  • calcium oxalate stones
  • calcium phosphate 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?

Some children with kidney stones have no symptoms. These stones are still in the kidney and have not moved to the ureter and are called “silent stones.” Other children can experience severe pain due to urinary obstruction. Common symptoms of kidney stones include:

Kidney stones can affect different children in different ways. Young children in particular may have 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 a child has too much of the minerals that make up the stone and not enough water in their 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 their 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. This is because bones that are inactive can’t regenerate themselves properly, which results in calcium being flushed into the system.

How we care for kidney stones at Boston Children’s Hospital

At Boston Children’s Hospital, we treat children with kidney stones in our dedicated Kidney Stone Program. We see children who have 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 team approach allows us to optimize your child’s care and work together to develop a treatment plan.

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

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