How do urinary stones form? The formation of urinary stones is the result of multiple factors, including: nutrition (e.g. high salt, sugar, protein, low intake of vegetables and dietary fiber, etc.), metabolism (e.g. cystinuria, abnormal metabolism of oxalic acid, abnormal calcium-phosphorus metabolism, high uric acid, etc.), drugs (e.g. vitamin D toxicity, corticosteroids, sulfonamides, etc.), acquired diseases (e.g. hyperparathyroidism, brake syndrome, cortisolism, gout etc.) and anatomical abnormalities (e.g. obstruction at the ureteropelvic junction, ureteral cysts, prostatic hyperplasia, urethral stricture, etc.). What are the sites of urinary tract stones? Stones can be found anywhere in the urinary tract and can be divided into upper urinary tract stones and lower urinary tract stones: upper urinary tract stones include kidney stones and ureteral stones, and lower urinary tract stones include bladder stones and urethral stones. The formation of stones is usually in the kidney or bladder, and all other urinary tract stones drift from these two places.