What Is a Kidney Stone?

A kidney stone forms when certain substances in the urine crystallize and build up into a hard mass. Size, location, and composition vary from person to person. Small stones sometimes pass on their own, while larger stones or those causing a blockage may require treatment.

Signs

The most common symptom is severe, intermittent pain in the back and flank (renal colic). This can be accompanied by nausea, vomiting, blood in the urine, frequent urination, and discomfort while urinating. Pain accompanied by fever may require urgent evaluation for infection.

Diagnosis

Evaluation involves urinalysis, blood tests, and imaging (ultrasound, and CT when needed). Imaging shows the size and location of the stone and whether there's a blockage in the urinary tract; this information guides the choice of treatment.

Treatment Methods

The treatment decision is based on the stone's size, location, composition, and the patient's condition. Small stones can often be monitored with adequate fluid intake and medication support and may pass on their own. When intervention is needed, the main modern methods are:

  • Extracorporeal shock wave lithotripsy (ESWL): Sound waves delivered from outside the body break the stone so the fragments can pass in the urine. It isn't surgery and can be a good option for stones of suitable size and location.
  • Ureteroscopy / RIRS (retrograde intrarenal surgery): The stone is broken up using a thin device and a laser advanced through the urinary tract. No incision is made; access is through the urinary tract. It's used for suitable stones in the ureter or kidney.
  • Percutaneous nephrolithotomy (PCNL): A small incision in the back is used to access the kidney and remove the stone. It's a leading option for larger stones.

Stone Treatment in Children

These methods can also be applied in children, though the choice of technique and equipment is tailored to the child's age and anatomy. Any underlying cause of stone formation in children is investigated separately as well.

Prevention

The single most important general recommendation for reducing stone recurrence is adequate fluid intake. Dietary recommendations and guidance related to stone composition vary by individual; a cause-directed evaluation is useful for those with a history of recurrent stones.

Frequently Asked Questions

Does every kidney stone require surgery?

No; most small stones can pass on their own with monitoring and fluid support.

Which method is best?

There isn't a single "best" method; the most suitable approach is chosen based on the characteristics of the stone and the patient.

Can stones come back?

Recurrence is possible; adequate fluid intake and cause-directed measures can help reduce the risk.