Symptoms and Diagnosis

Types of Stones

Dietary Prevention

Xray/ CT Scan/ Ultrasound/ IVP

Surgical Removal/ Lithotripsy

Causes of Stones

Genetic Causes

Medical Diseases


Metabolic Syndrome and Diabetes



Author Information



Not all kidney stones will spontaneously pass from the kidney out into the urine.  Most stones under .5cm will spontaneously pass from the kidney.  Most stones greater than 1cm will not pass.  If the stone must be removed two commonly employed methods are percutaneous nephrolithotrypsy (PCNL) and extracorporeal shock wave lithotripsy (ESWL).  The type of procedure depends on the type of stone and its size.  Typically, small stones can be treated with ESWL, while larger stones require PCNL. ESWL is typically not successful for cystine stones.  Some large struvite stones require a combination of PCNL and ESWL.  

ESWL (extracorporeal shock wave lithotripsy) This procedure uses sound waves to break apart the stone.  Originally, people were placed in large water baths which is good at transmitting sound waves.  Newer generation machines transmit the shock wave through a water cushion or tube which is placed over the patient.  The stone must be found by either ultrasonography or flouroscopy, which is like an xray machine but uses television monitors rather than xray film for constant monitoring.  Often as part of ESWL, the urologist will perform cystoscopy and place a stent (a small tube) that passes from outside the patient, through the urethra, up the ureter, and into the kidney.  This tube will remain in place for a few days.  It allows for easier passage of the tiny stone fragments that are created after exploding the stone with shock waves. 

ESWL can also be used successfully for stones that are stuck in the ureter.

PCNL (percutaneous nephrolithotrypsy): This procedure is more commonly used when ESWL cannot (e.g. cystine stones, large staghorns, unsuccessfuly ESWL, calcified aorta, and other causes).  First a tube is inserted into the patient's back into the kidney to create a tract.  A scope is run through the tract to directly visualize the stone inside the kidney.  Ultrasound equipment can then be inserted to break up the stone.  While watching the stone through the scope, the stone fragments can be grasped with special equipment and pulled through the tract out from the kidney.

Open Surgery:  Before the advent of PCNL and ESWL, open surgical procedures were performed.  This is less often necessary now, but sometimes is still performed especially for large complicated staghorn stones.