Urinary Tract Calculi I: Introduction

Renal calculi, or kidney stones, are hard mineral deposits that form in the urinary system.

Predisposing factors include excessive protein intake, antacid medications, anatomic abnormalities like horseshoe kidneys, dehydration in warm climates, and genetic predisposition.

Kidney stones are categorized by their chemical composition:

First, calcium stones, the most prevalent kidney stones, comprise calcium oxalate or calcium phosphate and can result from dehydration, excessive consumption of oxalate-rich foods like tea, or metabolic conditions like hyperparathyroidism.

Next, uric acid stones develop from high uric acid levels in the urine, often associated with gout, purine-rich diets such as meat, and low urine pH caused by diuretics or chronic diarrhea.

Third, struvite stones or magnesium ammonium phosphate stones are linked to urinary tract infections caused by urease-producing bacteria such as Proteus mirabilis, which increases urine pH and causes struvite stone formation.

Lastly, cystine stones arise from cystinuria, a genetic disorder that increases cystine levels in the urine due to poor solubility.