What is renal artery stenosis?

Renal artery stenosis is the narrowing of one or both of the renal arteries. These vessels supply blood to your kidneys. They also help the body control blood pressure.

What causes it?

The most common cause of renal artery stenosis is a buildup of fatty deposits called plaque. It can happen in either or both renal arteries. This is often called "hardening of the arteries," or atherosclerosis. The buildup can narrow the artery and reduce blood flow to the kidneys.

Renal artery stenosis can also be caused by fibromuscular dysplasia. This is a condition in which some of the cells that line the renal arteries grow or don't develop the right way. This growth can cause the arteries to narrow.

What are the symptoms?

Renal artery stenosis itself doesn't cause symptoms. But if it gets worse, it may cause high blood pressure. Or it may affect how well your kidneys work. Then you may have symptoms of kidney disease, such as shortness of breath or fluid buildup that causes swelling in your legs and feet.

Several things may make your doctor think that you have renal artery stenosis. These include blood tests that show that your kidneys don't work as well as they should. Or maybe you were diagnosed with high blood pressure at an early age. Or maybe medicine doesn't lower your blood pressure.

How is it diagnosed?

Your doctor will do a physical exam. Lab tests will be done, and the doctor will ask about your and your family's past health.

You may have a test that lets your doctor look at a picture of your kidneys and renal arteries. Tests that can do this include:

Duplex Doppler ultrasound.

This test uses sound waves to show how blood flows through a blood vessel.

Computed tomography (CT) angiogram.

It uses X-rays to make pictures of the renal arteries.

Magnetic resonance angiogram.

It uses a magnetic field and pulses of radio wave energy to make pictures of the renal arteries.

A catheter angiogram of the kidney.

It uses X-rays to make pictures of the blood flow in a blood vessel, such as the renal arteries.

How is it treated?

You may take medicine to lower blood pressure, cholesterol, and the risk of blood clots. You can also follow a heart-healthy lifestyle. Certain people may have angioplasty or surgery to improve blood flow to the kidneys. Treatment can help reduce damage to the kidneys and lower your risk of heart attack and stroke.

How can you care for yourself at home?

Caring for yourself when you have renal artery stenosis means doing things that will help slow or prevent it from getting worse. For example, take your medicines. Don't smoke. Eat heart-healthy foods, and be active. And manage other health problems, such as diabetes, high blood pressure, and high cholesterol.