USMLE Step 2 CK High-Yield Practice Test

Calcium oxalate stones are the most common type of nephrolithiasis, accounting for approximately 70-80% of all kidney stones. These stones form when there is an increased concentration of calcium and oxalate in the urine. Factors that can contribute to the formation of calcium oxalate stones include low fluid intake, dehydration, high dietary intake of oxalate-rich foods (such as spinach, nuts, and chocolate), as well as certain metabolic conditions that influence calcium and oxalate levels.

Understanding the prevalence of calcium oxalate stones is essential not only for diagnosis but also for management and prevention strategies. Patients who form these stones may benefit from increased hydration, dietary modifications to limit oxalate intake, and sometimes medications that reduce urinary calcium excretion.

In contrast, other types of stones, such as struvite stones, uric acid stones, and cystine stones, occur less frequently and have different underlying causes and risk factors. Struvite stones are associated with urinary tract infections, uric acid stones are linked to hyperuricemia or conditions leading to low urine pH, and cystine stones form in individuals with a genetic disorder that causes excess cystine in the urine. Understanding the specifics of calcium