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Rady Children's Specialists

Kidney Stones

What is a kidney stone?

A kidney stone is a “stone” that is made of things that naturally occur in your urine, like calcium. They can form anywhere in the urinary system from the kidneys, the tubes that drain the kidneys, or the bladder.

What are signs or symptoms of a kidney stone?

Kidney stones can cause pain when they begin to travel from the kidney down the tube to the bladder. The pain can be felt in the back or front and may travel down to the lower abdomen. Many times the pain is associated with nausea and vomiting. They can also cause blood in the urine, called hematuria.  Not all stones cause pain, but some are found in kids who have recurrent bladder or kidney infections.

What causes kidney stones in children?

The exact incidence of kidney stones in children is not known, however the number of children affected has been increasing. Stones are formed from the normal parts of urine such as calcium or uric acid. When the concentration of these particles becomes too high they stick together and begin to grow into a stone.  Our diets and hydration status can contribute to the stones that we form with high salt diets and dehydration being the biggest problems.

How do we test for a kidney stone?

In children, the primary test to evaluate for signs of a kidney stone is a renal bladder ultrasound, which is non-invasive and does not involve radiation. However, your doctor may choose to do additional testing with CT scan to better visualize or evaluate a kidney stone.

How are kidney stones treated?

Some stones do not require surgery but pass on their own. Some stones get stuck trying to pass and require surgery to help remove them.

  • Ureteroscopy uses a very small camera to look into the bladder and then the tube that leads up to the kidney. Some stones are small enough to pass a small basket around and pull out without breaking up. Some stones are large enough that they require breakage with a laser and removal of small pieces via the basket.
  • SWL (shock wave lithotripsy) is done for stones that are visible on X-ray. Children are placed under anesthesia for this procedure and the lithotripter delivers shock waves to the stone under X-ray guidance. There are no cuts or incisions. The child then passes the smaller stone pieces on his own.
  • PCNL (percutaneous nephrolithotomy) is done for very large stones growing in the kidney that are generally too large to undergo either ureteroscopy or SWL. A large camera is passed through the back directly into the kidney to remove stones. A nephrostomy tube, or a tube in the back that drains urine, is generally left in place for a period of time after this procedure.

How can kidney stones be prevented?

A 24-hour urine collection can help to determine what a child’s risk factors are for forming more stones in the future. Then, we can work on dietary changes or add medications to decrease risk of stone formation in the future.

Kidney stones are evaluated and treated at the multidisciplinary Stone Clinic