Fibromuscular Dysplasia (FMD)


Fibromuscular dysplasia (FMD) occurs when cluster of cells develops inside the blood vessel walls, causing it to narrow or bulge and restricting blood flow. These bulges can cause the blood vessels to appear "beaded" as multiple growths develop.

FMD commonly affects the carotid arteries, which run along the neck and supply blood to the brain. The condition can also affect blood vessels in the brain, the renal arteries that supply blood to the kidneys, and less commonly, blood vessels in the intestines, legs or arms.


Symptoms of FMD include:

  • Headaches
  • Neck pain
  • Lightheadedness
  • Poor kidney function
  • High blood pressure
  • Changes in vision
  • Numbness or weakness in the facial muscles
  • Cold limbs
  • Discomfort in limbs during movement

When the blood vessels of the brain are affected, the patient may experience a stroke. Symptoms of a stroke include:

  • Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
  • Sudden confusion
  • Sudden trouble speaking
  • Sudden trouble seeing in one or both eyes
  • Sudden trouble walking
  • Sudden dizziness, loss of balance or coordination
  • Sudden, severe headache with no known cause

Causes and Risk Factors

The cause of FMD is unknown, however, research indicates genetics, hormones and abnormal arteries all may play a part. More women than men are diagnosed with FMD, and most patients are diagnosed while in their 50's. Patients who smoke have an increased risk of developing the condition.


Diagnosis of FMD usually begins with a physical exam and a review of the patient's medical history and symptoms. A positive diagnosis of FMD is based on the patient’s symptoms as well as the findings of diagnostic tests.

Imaging tests, such as magnetic resonance imaging (MRI) or computed tomography (CT), can help the medical team better understand what is going on inside the body. An MRI or CT scan can be used to look for areas of the body that may be experiencing tissue damage due to limited blood flow. When the condition occurs in the brain these tools can help identify areas that resemble stroke conditions and can help determine what damage has occurred.

Other imaging tests may include an angiography, which will map the blood vessels using a special dye and imaging test. This can help identify areas where blood vessels are bulging or narrowing.


Treatment for FMD generally focuses on improving blood flow to the affected area.

For mild cases, an over-the-counter (OTC) medication to thin the blood, such as aspirin, may be recommended to help with headaches or neck pain. Anticoagulant medications may also be used to help increase the blood flow through the area and prevent clots from forming.

If the condition is more severe, surgical procedures to open up the narrowed or blocked blood vessel may be needed. This may include a balloon angioplasty or stenting.

For patients who have experienced a stroke, the Stroke Program at Cedars-Sinai provides a multidisciplinary treatment approach through a personalized treatment plan tailored to each patient. Patient care is generally broken down into three categories: stroke prevention, treatment immediately after a stroke, and post-stroke rehabilitation.

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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