This prospective observational case-control study will investigate whether the 2D:4D digit ratio is associated with urinary stone disease. Adults undergoing non-contrast computed tomography at Malatya Training and Research Hospital will be classified as cases if kidney and/or ureteral stones are detected and as controls if no urinary stones are detected and there is no previous history of stone disease or stone surgery. The lengths of the second and fourth fingers of both hands will be measured using a digital caliper by two independent observers who are blinded to the participant group. The study will also examine whether the 2D:4D ratio is associated with recurrent stone disease, stone burden, and bilateral or multiple stones.