Question: What causes Renal Artery Stenosis ?
Answer: About 90 percent of RAS is caused by atherosclerosisclogging, narrowing, and hardening of the renal arteries.2 In these cases, RAS develops when plaquea sticky substance made up of fat, cholesterol, calcium, and other material found in the bloodbuilds up on the inner wall of one or both renal arteries. Plaque buildup is what makes the artery wall hard and narrow. Most other cases of RAS are caused by fibromuscular dysplasia (FMD)the abnormal development or growth of cells on the renal artery wallswhich can cause blood vessels to narrow. Rarely, RAS is caused by other conditions.
Source: NIDDK

Question: Who is at risk for Renal Artery Stenosis? ?
Answer: People at risk for artherosclerosis are also at risk for RAS. Risk factors for RAS caused by artherosclerosis include - high blood cholesterol levels - high blood pressure - smoking - insulin resistance - diabetes - being overweight or obese - lack of physical activity - a diet high in fat, cholesterol, sodium, and sugar - being a man older than 45 or a woman older than 55 - a family history of early heart disease The risk factors for RAS caused by FMD are unknown, but FMD is most common in women and people 25 to 50 years of age.3 FMD can affect more than one person in a family, indicating that it may be caused by an inherited gene.
Source: NIDDK

Question: What are the complications of Renal Artery Stenosis ?
Answer: People with RAS are at increased risk for complications resulting from loss of kidney function or atherosclerosis occurring in other blood vessels, such as - chronic kidney disease (CKD)reduced kidney function over a period of time - coronary artery diseasenarrowing and hardening of arteries that supply blood to the heart - strokebrain damage caused by lack of blood flow to the brain - peripheral vascular diseaseblockage of blood vessels that restricts flow of blood from the heart to other parts of the body, particularly the legs RAS can lead to kidney failure, described as end-stage renal disease when treated with blood-filtering treatments called dialysis or a kidney transplant, though this is uncommon in people who receive ongoing treatment for RAS.
Source: NIDDK