Which statement about nephrolithiasis differences between sexes is true?

• A. Males 3-4x more common than females; calcium or uric acid stones; females more likely due to infection stones.
• B. Males more likely to have infection stones.
• C. Females are more likely to have stones overall.
• D. There is no difference between sexes.

Answer: (C)

Understanding how nephrolithiasis differs by sex requires looking at how risk factors and stone types vary between men and women. Infection-related stones (such as struvite) arise from urinary tract infections, and UTIs are more common in women, which increases the likelihood of stones in females. In addition, factors unique to women—like pregnancy-related urinary changes and certain metabolic or health trends in some populations—can strengthen the overall risk of stone formation in females. Because of these influences, the statement that females are more likely to have stones overall aligns with observed patterns in many settings, making it the best-supported option.

The other statements contradict these sex-specific risk patterns: one attributes a much higher overall incidence to men and ties it to calcium or uric acid stones, another claims men are more prone to infection stones, and another asserts there’s no difference between sexes.