What is Fibromuscular Dysplasia?

Fibromuscular dysplasia (FMD) is a disease that can cause narrowing (stenosis), tearing or aneurysms of the arteries, and results from abnormal cell growth within the artery walls.[1,2]

It can affect the renal arteries that supply the kidneys(FIG 1.), the carotid arteries that supply the brain, and, less commonly, the arteries of the abdomen.

FMD can cause hypertension, strokes, heart attacks, and severe pain in affected areas.

In the U.S.A, there have been a few thousand confirmed cases of FMD, but some experts believe it affects up to 5% of the population. When presumably healthy kidney donors are screened with X-rays, FMD has been found in close to 4%.[3][4]

FMD is caused when cells in the walls of the arteries undergo abnormal growth, resulting in the vessels becoming narrowed. Symptoms only occur when the blood flow is decreased enough. Because of this, FMD is often diagnosed incidentally in the absence of any signs or symptoms during an imaging study. When the blood vessel is filled with dye for an X-ray, it will show a characteristic "string of pearls" appearance.






1. Online 'Mendelian Inheritance in Man' (OMIM) 135580
2. Plouin PF et al. Orphanet J Rare Dis 2007;2:28.
3. The 'Rare' Disease That Isn't; Often Under diagnosed, FMD May Afflict Up to 5% of Americans, by Thomas M. Burton, Wall Street Journal, June 27, 2009
4. Fibromuscular Dysplasia, Slovut DP, Olin JW N Engel J Med 350:1862, April 29, 2004 Review Article

For the latest Patient Information Data click here.

For our FMDAA brochure used at the Hypertension Conference, Sydney, 2012 click here.


Optimising the care of people with FMD download here.

Dr Scott Wilson

B.Med.Sci (Hons) MB.BS (Hons) PhD FRACP

Consultant Physician & Nephrologist

Clinical Lead in Dialysis & ESKD Therapies