This document discusses renal calculi (kidney stones). It defines kidney stones as solid masses that form in the kidneys from mineral deposits in urine. The main types are calcium oxalate, calcium phosphate, struvite, uric acid, and cystine stones. Risk factors include diet, fluid intake, metabolic disorders, and urinary tract infections. Symptoms include severe flank or abdominal pain. Diagnosis involves blood and urine tests, along with imaging like ultrasounds, CT scans, or intravenous pyelograms. Treatment consists of pain medication, increased fluid intake, and sometimes surgical procedures like lithotripsy or percutaneous nephrolithotomy to break up or remove stones.