What are the leading causes of nephrolithiasis?
The most common causes of nephrolithiasis are the various types of polygenic idiopathic hypercalciuria (IH): absorptive hypercalciuria (AH) types AH-I to AH-III (renal phosphate leak) and renal hypercalciuria (RH). Other causes are primary hyperparathyroidism, hyperoxaluria, hyperuricosuria, hyperphosphaturia, hypocitraturia, hypomagnesuria, infection stones, gouty diathesis, renal tubular acidosis, cystinuria, calcifying nanoparticles, and alterations in the microbiome. Rarely, kidney stones may form from xanthine, triamterene, monosodium urate, ephedrine, guaifenesin, ciprofloxacin, and sulfonamides, and more commonly from protease inhibitors indinavir, atazanavir, and darunavir. Patients with idiopathic nephrolithiasis make up 10% to 20% of “stone formers” in whom routine workup yields no identifiable cause.