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 certain foods, dehydration, and metabolic disorders. Symptoms include severe flank or abdominal pain. Diagnosis involves tests like ultrasound, IVU, or CT scan. Treatment includes pain medication, increased fluid intake, surgery like lithotripsy or percutaneous nephrolithotomy, and preventing recurrences through diet and lifestyle changes.