Kidney Stone Testing and Analysis 

Analyzing passed kidney stones can help guide a doctor’s treatment recommendations.  

Oddly shaped crystals or masses that form in the kidney are called kidney stones. They are incredibly common, afflicting about one in every 10 people in their lifetimes. As the kidneys filter blood to remove water and waste products, urine is produced. Sometimes kidney stones—which can range in size from a grain of sand up to larger than a golf ball—also form and attempt to pass through the urinary tract.  
 In most cases, kidney stones will pass through the urinary system on their own, although the process can be extremely painful as the stone stretches, irritates or damages the ureter walls as it passes through. In other cases, a stone can get trapped in the ureter, and surgery is required to remove it. When a kidney stone is removed or passes on its own, your doctor may want to analyze the stones. 

Why is Kidney Stone Testing and Analysis Performed? 

Symptoms that may lead your doctor to recommended kidney stone testing and analysis include: 

  • Sharp pain in the abdomen or groin 
  • Back pain 
  • Blood in the urine
  • Pain when urinating 
  • Frequent need to urinate 

Kidney stones form when there is a higher-than-normal concentration of certain chemicals in the urine. When this occurs, the chemicals are no longer soluble and form crystals. Chemicals that form kidney stones include: 

  • Calcium oxalate 
  • Calcium phosphate 
  • Uric acid 
  • Struvite, or magnesium ammonium phosphate 

More rarely, cystine and xanthine can also form kidney stones. 

Kidney stone analysis uses one or more different tests to look at and determine the composition of the stone. A stone may consist of one chemical compound or have different chemicals in different layers. Identifying the composition of the kidney stone can help your doctor understand what caused the stone to form and if there’s a way to prevent more stones from forming. 

What to Expect 

Kidney stone analysis and testing is completed after a stone is filtered out of the urine or removed from the urinary tract. The stone is sent to a laboratory for analysis, where the stone’s size, shape, weight, color and texture are recorded. A picture of the stone may be taken for documentation. In addition, the stone may also be split apart so that its layers can be observed and tested and the stone’s composition can be determined.  

The types of chemicals present in the stone can help determine the cause of formation. Many times, not drinking enough water can increase the risk for kidney stones, but other underlying problems may be the cause. For example, a calcium oxalate stone can indicate that you release excess calcium or oxalate into your urine, which can be caused by dietary factors, metabolic disorders or an excess of parathyroid hormone, among others.  


In general, kidney stone analysis and testing is an effective diagnostic method to help prevent the formation of more stones or treat an underlying cause. The urologic experts at Tampa General Hospital frequently perform kidney stone testing to provide patients with the world-class care and treatment for their specific needs.