Fibromuscular dysplasia is a condition that causes narrowing (stenosis) and enlargement (aneurysm) of the medium-sized arteries in your body. Narrowed arteries can reduce blood flow and affect the function of your organs.

Fibromuscular dysplasia appears most commonly in the arteries leading to the kidneys and brain. Fibromuscular dysplasia can affect other arteries, including those leading to your legs, heart, abdomen and, rarely, the arms. It's possible to have more than one affected artery.

Treatments are available, but there isn't a cure for fibromuscular dysplasia.

Many people who have fibromuscular dysplasia don't have any symptoms. For those who do, signs or symptoms of the disease depend on which artery or arteries are affected.

If the arteries to the kidneys are affected, common signs and symptoms include:

• High blood pressure
• Poor kidney function

If the arteries affected supply blood to the brain, signs and symptoms might include:

• Headache
• Pulsating ringing in your ears (tinnitus)
• Dizziness
• Sudden neck pain
• Stroke or transient ischemic attack (TIA)

When to see a doctor

If you have fibromuscular dysplasia, seek medical attention immediately if you have signs or symptoms that could indicate a stroke, such as:

• Sudden changes in your vision
• Sudden changes in your ability to speak
• Sudden or new weakness in your arms or legs

If you have other signs or symptoms and are concerned about your risk of fibromuscular dysplasia, see your doctor.

Tell your doctor about your family health history because fibromuscular dysplasia can run in families, although that's rare. There's no genetic test for fibromuscular dysplasia.

The cause of fibromuscular dysplasia is unknown. However, several factors might play a role.

• Hormones. Researchers think female hormones might play a role in the development of the disease. Fibromuscular dysplasia is not linked to women's use of birth control pills, number of pregnancies, or age when they gave birth.
• Genetics. If someone in your family has fibromuscular dysplasia, you might get the condition, too.

Several things may make you more likely to develop fibromuscular dysplasia.

• Sex. Fibromuscular dysplasia is more common in women than it is in men.
• Age. Although it can affect people of any age, fibromuscular dysplasia tends to be diagnosed in people in their 50s.
• Smoking. People who smoke appear to have an increased risk of developing fibromuscular dysplasia. For those already diagnosed with the disease, smoking increases the risk for more-serious disease.

Fibromuscular dysplasia can cause a number of complications, including:

• High blood pressure. The narrowing of the arteries of the kidneys causes higher pressure on your artery walls, which can lead to further artery damage, heart disease or heart failure.
• Dissected artery. Fibromuscular dysplasia and tears in the walls of your arteries often occur together. This process is called arterial dissection or spontaneous coronary artery dissection (SCAD), when it occurs in the arteries of the heart or coronaries. Dissections can limit blood flow to the organ supplied by the injured artery.
• Aneurysms. Fibromuscular dysplasia can weaken the walls of the arteries it affects, creating a bulge (aneurysm). An aneurysm rupture can be life-threatening. Aneurysms need to be monitored and sometimes require surgery to prevent rupture.
• Stroke. If you have a dissected artery leading to your brain or if an aneurysm in an artery to your brain ruptures, you can have a stroke. High blood pressure also can increase your risk of a stroke.

Your doctor might check for the condition if he or she hears an abnormal sound in your upper stomach area or your neck that could be caused by the narrowed arteries. If someone in your family has or had fibromuscular dysplasia or aneurysm, your doctor might recommend checking you for the condition, even if you have no signs or symptoms.

Your doctor will perform a physical exam and order blood tests, including blood sugar and cholesterol levels, to check for signs of atherosclerosis, another condition that can narrow your arteries.

Tests to diagnose fibromuscular dysplasia could include:

• Duplex ultrasound. This noninvasive imaging test can determine if an artery is narrowed. An instrument called a transducer is pressed to your skin to send sound waves into your body. They bounce off cells and body structures, showing how fast your blood flows and the size and shape of the blood vessels.
• CT angiogram. This test provides cross-sectional images of your body, which can show narrowing in the arteries, aneurysms and dissections. You lie on a narrow table, which slides through a doughnut-shaped scanner. Before the test starts, you'll receive an injection of a dye, which highlights areas of the body being examined.
• Magnetic resonance (MR) angiogram. This test uses a magnetic field and radio waves to create images of the body. It can see if you have an aneurysm or dissection. During the test, you'll lie on a narrow table that slides into a tubelike machine that's open on both ends. Before the test starts, you might receive an injection of a dye, which highlights areas of the body being examined.
• Catheter-based angiography. During this commonly used test for fibromuscular dysplasia, a thin tube (catheter) is inserted into one of your arteries and moved until it reaches the area your doctor wants to examine. A tiny amount of dye is injected and X-rays are used to examine the area.

The most common form of fibromuscular dysplasia looks like a "string of beads" on imaging tests. Other forms of fibromuscular dysplasia have a smooth focal appearance.

Once you've been diagnosed with fibromuscular dysplasia, your doctor will follow you clinically. Occasionally, for example if you have an aneurysm, or if your symptoms change, you may need repeat imaging to monitor the arteries.

Treatment for fibromuscular dysplasia depends on the symptoms, the site of the narrowed artery and other health conditions you have, such as high blood pressure. If you don't need treatment at the time, your doctor might recommend watchful waiting.

Medications

Treatment with high blood pressure medications is recommended for people with fibromuscular dysplasia who have hypertension, even if they have a procedure to correct the condition. Several types of medications are available:

• Angiotensin-converting enzyme (ACE) inhibitors, such as benazepril (Lotensin), enalapril (Vasotec) or lisinopril (Prinivil, Zestril), help relax your blood vessels.
• Angiotensin II receptor blockers. These medications also help relax your blood vessels. Examples of this class of medications include candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar) and valsartan (Diovan).
• Diuretics. These drugs, such as hydrochlorothiazide (Microzide), help remove excess fluid from your body and may be used with other blood pressure medications.
• Calcium channel blockers, such as amlodipine (Norvasc), nifedipine (Procardia) and others, help relax your blood vessels.
• Beta blockers, such as metoprolol (Lopressor), atenolol (Tenormin) and others, slow your heartbeat and block adrenaline.

Your doctor might advise you take a daily aspirin to reduce your risk of stroke. But don't start taking an aspirin without talking to your doctor first.

Some medications used to treat hypertension can affect the way your kidneys work. Your doctor might recommend blood and urine tests to make sure your kidneys are working normally once you start taking these medications.

Surgery or other procedures

Percutaneous transluminal angioplasty (PTA)

This procedure is preferred over surgery and is usually done at the same time as a catheter-based angiogram. During an angiogram, dye is injected through a catheter into an artery. X-rays show how the dye travels through the artery, revealing narrowed areas. A wire is threaded to the artery, and a catheter with a balloon is inserted into the narrowed area.

The balloon is then inflated to open the narrowed part of the artery. Rarely, a metal mesh tube (stent) may be placed inside the weakened part of the artery to help prevent it from rupturing.

Surgical revascularization

Surgery to repair the damaged artery is rarely recommended. It's usually only done when there are complications. However, if PTA is not an option and the narrowing of your arteries is severe, your doctor might recommend a more invasive approach with surgery to repair or replace the narrowed portion of the artery. The type of surgery depends on the site of the narrowed artery and how damaged the artery is.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance. For example, you might need to fast for several hours before the tests. Also, bring a family member or friend to your appointment, if possible, to help you remember the information you're given.

Make a list of:

• Your symptoms and when they began
• Key personal information, including a family history of fibromuscular dysplasia, aneurysms, heart disease, stroke or high blood pressure
• All medications, vitamins or other supplements you take, including doses
• Questions to ask your doctor

For fibromuscular dysplasia, some basic questions to ask your doctor include:

• What's the most likely cause of my symptoms?
• What tests will I need?
• What treatments are available? What do you recommend for me?
• What's an appropriate level of physical activity?
• How often should I be monitored for fibromuscular dysplasia?
• I have other health conditions. How can I best manage these conditions together?
• Should I see a specialist?
• Are there brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you questions, such as:

• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• Does anything seem to improve your symptoms?
• What, if anything, appears to worsen your symptoms?