Nephrolithiasis is a common disorder that occurs in about 10% of the adult population in Western countries. About 1 in a 1000 people must be treated every year in the A&E or hospitalised due to kidney stone-related colic. Men are, from 5:1 to 2:1, more often affected than women. 80% of the stones consist of calcium in the form of the crystalline oxalate or phosphate, only 10% of uric acid and the rest from cystine or magnesium ammonium phosphate (“infection stones”). The main cause of calcium stones is an unbalanced salt concentration of the urine, caused either through an increased excretion of calcium or a decreased urine volume. Factors affecting the renal excretion of calcium are shown in Table 17.1 . In 35% of cases, the hypercalciuric nephrolithiasis is a family-related disease.