Gender words are used here to talk about anatomy and health risk. Use this information in a way that works best for you and your doctor as you talk about your care.

Fibromuscular dysplasia (FMD) is a rare disease. It causes abnormal cell growth in some arteries in the body. Arteries are blood vessels that send oxygen-rich blood around the body and to your organs.

Arteries are made of different kinds of cells. They have muscle cells, fibrous cells, elastic cells, and smooth cells. With FMD, the muscle and fibrous cells overgrow in parts of some arteries. This causes those areas to be thicker. There is less room inside for blood flow. They can become fully blocked, bulge, or even tear.

FMD most often happens in:

• Renal arteries. These are the arteries that send blood to the kidneys.
• Carotid and vertebral arteries. These are arteries in the neck that send blood to the brain.

FMD may also happen in arteries in the belly (abdomen). These arteries send blood to the liver, spleen, and intestines. It may also happen in arteries in the arms and legs.

Researchers don't know yet what causes FMD. They are looking at causes such as genes and hormones. They are also looking at tobacco use, some medicines, and other risk factors.

Females who are under age 50 are more likely to have FMD. This may be due to certain hormones playing a part. You are more at risk if a brother or sister has FMD.

People who have any of these may be more at risk of FMD:

• Ehlers-Danlos syndrome type I.V. (vascular)
• Alport syndrome
• Pheochromocytoma
• Marfan syndrome
• Moyamoya disease

Some people don't have symptoms. Other people may have symptoms from the problems FMD can cause. They may have:

• High blood pressure
• Headaches
• Whooshing sound in the ears (pulsatile tinnitus)
• Belly pain after eating
• Pain in arms or legs with exercise
• Different blood pressure in each arm

The symptoms of FMD can be like other health conditions. Make sure to see your doctor for a diagnosis.

Your doctor will ask about your symptoms and medical history. They may also ask about your family's medical history. They will give you a physical exam. The physical exam may include listening to the blood flow in some arteries. The doctor may take your blood pressure.

An imaging test called an arteriogram will likely be done to diagnose the problem. Your doctor will insert a catheter into a large blood vessel and inject a special contrast dye. The contrast dye causes the blood vessels to appear on the X-ray image. This shows the inside shape of the artery.

There is no treatment to cure FMD, so treatment is done to manage problems that it causes.

Medicines may be prescribed to:

• Treat high blood pressure
• Prevent and manage headaches
• Reduce the risk of blood clots

Other treatments may include:

• Angioplasty. This is a procedure to widen an artery that is narrowed due to FMD. It will help increase the blood flow. A thin, flexible tube (catheter) is put into the artery. A tiny balloon is inflated in the area that is narrow. This helps widen that area and increase blood flow.
• Surgery. This may be done to treat a bulging artery (aneurysm) caused by FMD. A tiny mesh tube or coil may be put in the artery. This is to help prevent the aneurysm from tearing (rupture).

Areas of FMD in an artery are at higher risk of:

• Narrowing (stenosis)
• Bulging (aneurysm)
• Tears (dissection)

Severe FMD in a carotid artery may lead to a blood clot (stroke) or a blood vessel bulge (aneurysm) in the brain. Either of these can cause bleeding in the brain.

Researchers don't yet know how to prevent FMD.

People with FMD should not smoke, vape, or use other tobacco or nicotine products. Use of tobacco and nicotine causes problems with blood vessels. It can be hard to quit, but you don't have to do it alone. Go to smokefree.gov for resources and support to help you quit. Talk with your doctor about support near you.

The following websites can provide information and support and connect you with others who have FMD:

• Fibromuscular Dysplasia Society of America (FMDSA)
• RareConnect

Contact your doctor if you are experiencing new FMD symptoms or if your symptoms are getting worse.

• Fibromuscular dysplasia (FMD) causes abnormal cell growth in some arteries in the body. There is less room inside for blood flow. They can become fully blocked or even tear.
• Females who are under age 50 are more likely to have FMD.
• Symptoms may include high blood pressure, headaches, and a whooshing sound in the ear.
• Diagnosis is done with an arteriogram to look at your arteries.
• There is no treatment to cure FMD, so treatment is done to manage problems that it causes. Treatment may include medicines and angioplasty.
• People with FMD should not smoke, vape, or use other tobacco or nicotine products.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours, or on weekends or holidays.