Types of Kidney Stones
More than 70 percent of kidney stones have some type of calcium component. These include calcium oxalate or calcium phosphate, alone or in combination. Non-calcium kidney stones occur much less frequently. These may be comprised of struvite, uric acid, cystine or unknown compounds.
How Do Stones Occur?
To form a stone, a crystal has to form within the urine. This solid crystal formation is affected by temperature, the pH of the urine and the amount of certain substances in the urine.
Although in some cases how a stone was formed is understood, for many people it is unclear. Examples of well-understood cases include cystine stones that are due to a genetic error; calcium stones caused by a high level of calcium in the bloodstream from primary hyperparathyroidism; and uric acid stones that are associated with gout.
Common Risk Factors
1) Dietary excesses including too much calcium intake.
2) Medications such as antacids, protein supplements, indinavir (for HIV), acetazolamide, triamterene, thiazides (diuretics) and vitamins C and D.
3) Environmental factors such as dehydration.