Objective: To present a simple classification of the most frequent renal calculi that relates each type of calculus with the main possible etiologic factors linked to its formation (mainly urinary biochemical parameters).
Methods: The macro, microstructure and composition of 2,500 renal calculi were studied by appropriate combination of stereoscopic microscopy, IR spectroscopy and scanning electron microscopy + X-ray microanalysis. The information obtained were related with the main urinary biochemical parameters, determined by conventional analytical procedures.
Results: Ten main categories of renal stones, covering over 95% of all conceivable calculi, are distinguished based on their composition and structure. Etiologic factors, mainly urinary biochemical parameters, leading to the formation of stone of every category are specified.
Conclusions: From the detailed study of the renal calculus important etiologic factors can be deduced. Such information complements and confirms the urinary biochemical studies. As a consequence, the corresponding treatment can be better established.