Risk factors for the development of renal stones include age between 20 and 50 years, male gender, sedentary lifestyle, and family history. Stones form as a result of metabolic abnormalities including milk-alkali syndrome, sarcoidosis, Crohn disease, recurrent UTIs, and laxative abuse. They can be classified as calcium, struvite, uric acid, or cystine. The majority of stones are composed of either calcium oxalate alone or with calcium phosphate and hypercalciuria, due to excessive dietary intake, hyperparathyroidism, or peptic ulcer disease, is a major risk factor in the development of renal stones. The size and location of the stone are the major determinants of the severity of patient symptoms. Because of the urinary outflow obstruction and resultant urostasis, patients with renal stones are at increased risk of pyelonephritis, perinephric abscess, sepsis, and other severe urinary tract infections. The presence of comorbid urinary infection, rather than stone size or location, is the major cause of renal dysfunction.