Prevention and treatment of nephrolithiasis: a review on the role of spa therapy.

The prevalence and incidence of nephrolithiasis is reported to be increasing across the world. It is a disease of increased urinary concentration of stone-forming salts. The physiochemical mechanism of stone formation includes precipitation, homogenous/heterogeneous nucleation, growth, aggregation and concretion of various modulators in urine. Necessary condition to develop stones is urinary supersaturation, due to reduced urinary volume or to an excesses solutes. Fluid intake is the main determinant of urine volume. Urine dilution can significantly decrease both the cristallization rate of the urinary salts and the aggregation of the crystals. A correct fluid intake can acts on different effects: urinary tract washing, urinary volume increasing and dilution of solutes. In addition mineral waters have other particular features: greater diuretic effect, more important urinary dilution with solutes and microbial concentration reduction, pH changes, superior washout effect due to mechanical effects and ureteral contractions. Adequate water intake is the most important conservative strategy in urolithiasis-prevention; particulary hydropinotherapy with oligomineral water should be considered as an important instrument to prevent stones in predisposed subject (family members of people suffering from kidney stones), to reduce relapses, and can help both in eliminating the stone fragments also after extracorporeal shock wave lithotripsy. Is recommended a management with increased mineral water intake to promote urine volume of at least 2.5L each day to prevent stone formation. Obviously water intake shall be varied in relation to the presence of contraindications or any diseases.