Kidney stones are hard, calcified, mineral deposits that form in the kidneys. It could be caused by a variety of factors including a high salt intake, obesity and consumption of certain medications or supplements. The stones typically form in places where un-expelled urine stagnates and causes a mineral build-up over time. It can occur in the kidneys, ureters or bladder. Passing a kidney stone can be a very painful process. However, they don’t usually cause any permanent damage if they are discovered in time. If the kidney stone becomes large and forms a urinary obstruction, it may require surgical removal.