Types of Urine Crystals

Urinary stones (or crystals) can vary in size from small to very large and can develop anywhere in the urinary tract. They frequently cause no symptoms unless frequent infections lead to investigation or the ureter becomes obstructed.

Features

• Urinary stones can be caused by excessive amounts of insoluble salts in the urine, insufficient fluid intake, immobility, infection, poor diet or as a result of an underlying condition, such as a parathyroid tumor or gout.

Calcium Stones

• Approximately 75 percent of urinary stones are calcium (phosphate, oxalate or carbonate) stones, caused by high calcium levels in the urine or highly alkaline urine, according to Barbara E. Gould, MEd, author of "Pathophysiology for the Health Professions." Calcium oxalate stones are often the result of vegetarian diets that lead to increased levels of oxalate in the urine.

Struvite Stones

• Struvite (magnesium ammonium phosphate) stones, which are more common in women, are usually the result of infection of the urinary tract.

Uric Acid Stones

• Uric acid stones develop as a result of excessive uric acid in the system (hyperuricemia), usually due to gout, high purine diets or cancer chemotherapy drugs.

Treatment

• Small stones often pass eventually without medical attention. Treatment options for larger stones (of all types) include fragmentation using shockwave or laser procedures, drug therapy and, in some cases, surgical removal.