The pathogenesis of idiopathic hypercalciuria: an alternative hypothesis.

Currently, four hypotheses attempt to explain the pathogenesis of idiopathic hypercalciuria. Proposed theories include hypersecretion of parathyroid hormone, hyperabsorption of calcium by the gastrointestinal tract, hyperreabsorption of calcium by the kidney, and hyperexcretion of phosphate by the kidney. These hypotheses are more descriptive than explanatory. A new hypothesis is suggested which encompasses the divergent findings. Idiopathic hypercalciuria may result from hypersecretion of parathyroid hormone which is active at the gastrointestinal and bone target site but is partially defective at its renal site of action.