Renal artery stenosis occurs when an artery in the kidney narrows. This causes a decrease in blood flow to that kidney. The kidneys are a pair of bean-shaped organs. They filter and remove waste from the blood. Stenosis is narrowing that restricts an opening.

The Kidney and Its Main Blood Vessels
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Each kidney regulates the body’s blood pressure to make sure that each organ has enough oxygenated blood. This happens by activating the renin-angiotensin hormone system.

Renal artery stenosis triggers the release of these hormones. This release causes hypertension, which is also known as high blood pressure.

There are several diseases of arteries that can cause them to become narrowed, including: