The exact reason why these stones form is usually unknown, but there are some known risk factors like hypercalcemia and hypercalciuria, having too much calcium in the blood and urine, respectively.

结石形成的确切病因至今未明，但存在一些已知的危险因素，比如说高钙血症、高钙尿症，即血液和尿液中钙含量相对较高。