What causes kidney stones?
The kidneys regulate levels of fluid, minerals, salts, and other substances in the body. When the balance of these compounds changes, kidney stones may form. There are four types of kidney stones, each made of different substances. Uric acid and cystine are two compounds that may comprise kidney stones. Factors known to increase the risk of kidney stones include dehydration, family history, genetics, and the presence of certain medical conditions. Having one or more family members with a history of kidney stones increases the risk of the condition.