Definition

The kidneys filter wastes from the blood and make urine. When the blood vessels that supply the kidneys with blood narrow, it’s called renal artery stenosis. The narrowing lowers the amount of blood flowing to one or both kidneys. Problems in both can lead to kidney failure.

The Kidney and its Main Blood Vessels Copyright © Nucleus Medical Media, Inc.

Causes

The kidneys control blood pressure. They help make sure the body has enough oxygen and blood. Narrowing causes blood pressure to go up. High blood pressure is a leading cause of stroke and heart attack.

The 2 most common causes are:

• Atherosclerosis —Plaque builds up in the arteries and blocks blood flow.
• Fibromuscular dysplasia—Muscle and tissue thicken on the artery wall and harden into rings. The rings block blood flow.

Risk Factors

Risk is higher if you:

• Have high blood pressure
• Have a blocked blood vessel in another part of the body
• Had a stroke or heart attack
• Smoke
• Have diabetes
• Have high cholesterol

Symptoms

Most people don’t have problems. When they do appear, they may cause:

• Chest pain
• Breathing problems from fluid buildup in the lungs
• Headache
• Lightheadedness

Diagnosis

The doctor will ask about your symptoms and health history. You may also have:

• A physical exam
• Blood pressure readings
• Blood and urine tests to look for certain proteins or other markers
• Imaging tests:
  • Renal ultrasound
  • CT angiography
  • MR angiography
  • Angiography

Treatment

Care involves lowering blood pressure. This will help lower stress on the kidneys. Care may involve:

• Quitting smoking, getting regular exercise, or eating better foods
• Medicines to lower blood pressure
• Surgery such as:
  • Percutaneous angioplasty—using a balloon or stent to open the artery
  • Bypass—rebuilding a blood vessel by going around the block
  • Remove one or both kidneys— nephrectomy

Prevention

There aren’t specific steps to prevent this condition.