Mechanisms of stone formation--an overview.

We have compiled a broad overview of the genesis of urinary stones. Central to the theses given are precise definitions of stone as opposed to stone disease. In terms of mechanisms, a kinetic point of view is essential to any formulation relating to stone formation. It is necessary to comprehend the kinetic approach, an understanding of nucleation, growth and aggregation, if one is to appreciate the final product--the stone. Certain fundamental concepts are reviewed which are critical in grasping these phenomena. Not to be forgotten is that the purely physical chemical aspects of stone formation are insufficient to explain all facets of the process. Therefore, interactions between crystals and tissue are explored in suggesting a unifying hypothesis for upper tract stone disease.