Causes
The two main causes of renal artery stenosis include:
- Atherosclerosis of the renal arteries. Atherosclerosis is the buildup of fats, cholesterol and other substances (plaques) in and on your artery walls. As the deposits get larger, they can harden, reduce blood flow and cause scarring of the kidney. Eventually, narrowing of the artery can result. Most cases of renal artery stenosis occur because of atherosclerosis.
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Fibromuscular dysplasia. In fibromuscular dysplasia, the muscle in the artery wall grows abnormally. The renal artery can have narrow sections alternating with wider sections, giving a beadlike appearance in images of the artery.
The renal artery can narrow so much that the kidney doesn't receive an adequate supply of blood and can become damaged. This can happen in one or both kidneys. Experts don't know what causes fibromuscular dysplasia, but the condition is more common in women and may be something that's present at birth (congenital).
Atherosclerosis and fibromuscular dysplasia can affect other arteries in your body as well as your kidney (renal) arteries and cause complications.
Rarely, renal artery stenosis results from other conditions such as inflammation of the blood vessels (vasculitis); a nervous system disorder that causes tumors to develop on nerve tissue (neurofibromatosis); or a growth that develops in your abdomen and presses on your kidneys' arteries (extrinsic compression).
Source: http://www.mayoclinic.com