<prompt> Most common cause of renal aery stenosis above 50 years of age is ?AtherosclerosisFMDTakayasu aeritisRCC  <response>: Atherosclerotic renal aery stenosis is common and prevalence increases with age. Large vessel renal aery occlusive disease can result from extrinsic compression of vessel ,intimal dissection, fibromuscular dysplasia, or most commonly atherosclerotic disease. Ref:Harrison 20 th edition pg no 1906 