Nephrolithiasis is a condition in which a hard mass (kidney stone) forms in the urinary tract (1,2). Risk factors for stone formation include low urinary volume, high urinary concentrations of crystal-forming substances (e.g. calcium, oxalate, phosphate, sodium and uric acid) and low urinary concentrations of crystal-inhibiting substances (e.g. citrate and magnesium) (1,2).
There are different types of kidney stones, with calcium oxalate stones being the most common (1,2). Stone formation