Fibromuscular dysplasia

Last updated: February 2, 2022

Summarytoggle arrow icon

Fibromuscular dysplasia (FMD), a disease that primarily affects young to middle-aged women, is characterized by the proliferation of connective tissue and muscle fibers within the arterial vessel walls. The resulting stenosis impairs perfusion of the affected organ, causing ischemia. The symptoms of fibromuscular dysplasia vary depending on the site and the degree of stenosis of FMD. The renal, internal carotid, and vertebral arteries are predominantly involved. Carotid and vertebral artery involvement may present with transient ischemic attack (TIA) and/or stroke, while patients with renal FMD usually present with secondary hypertension and chronic renal insufficiency. Bruits at the costovertebral angle and the carotid region are characteristic findings of renal and carotid artery involvement respectively. In rare cases, patients may present with mesenteric ischemia and/or peripheral artery disease as a result of splanchnic or peripheral arterial involvement. The “string of beads” sign, a characteristic finding on angiography, distinguishes FMD from other causes of arterial occlusion. All patients with renal FMD should be treated with ACE inhibitors and/or ARBs, while those with carotid artery involvement should be placed on stroke prophylaxis (low-dose aspirin therapy). Balloon angioplasty without stenting is the definitive treatment.

Epidemiologytoggle arrow icon

  • Age of onset: typically 30–50 years, but can manifest at any age
  • Sex: : > (8:1)
  • Ethnicity: increased prevalence among the white population


Epidemiological data refers to the US, unless otherwise specified.

Pathophysiologytoggle arrow icon

Fibromuscular dysplasia (FMD) is an idiopathic, non-inflammatory, non-atherosclerotic, developmental condition that primarily affects small and medium-sized muscular arteries.


The most commonly encountered histology is medial fibroplasia.


Disease localization


Clinical featurestoggle arrow icon

The symptoms of fibromuscular dysplasia are nonspecific and vary depending on the site of FMD, the degree of stenosis, and the underlying pathology (e.g., arterial dissection).


Diagnosticstoggle arrow icon


Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon


Referencestoggle arrow icon

  1. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015
  2. Olin JW. Clinical manifestations and diagnosis of fibromuscular dysplasia. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: June 3, 2015. Accessed: February 14, 2017.
  3. Wilson JA. Fibromuscular Dysplasia. Fibromuscular Dysplasia. New York, NY: WebMD. Updated: April 14, 2014. Accessed: February 14, 2017.
  4. Varennes L, Tahon F, Kastler A, et al. Fibromuscular dysplasia: what the radiologist should know: a pictorial review. Insights Imaging. 2015; 6 (3): p.295-307.doi: 10.1007/s13244-015-0382-4 . | Open in Read by QxMD
  5. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Elsevier Saunders ; 2014
  6. Kirkwood ML. Extracranial carotid artery aneurysm. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: January 27, 2017. Accessed: February 7, 2017.
  7. Olin JW. Treatment of fibromuscular dysplasia of the renal arteries. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: September 8, 2015. Accessed: February 14, 2017.
  8. Liebeskind DS. Cerebral Aneurysms. Cerebral Aneurysms. New York, NY: WebMD. Updated: August 4, 2016. Accessed: February 14, 2017.

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