About 5 million Americans, mostly women, suffer from a rare disease that they most probably have never heard of, but the condition could lead to high blood pressure, stroke and aneurysms.

The condition called fibromuscular dysplasia (FMD) is a rarely diagnosed disease that causes narrowing, or stenosis, in one or more arteries in the body. The most common symptoms of the disease are high blood pressure, headache and rhythmic hearing in the ears. Other symptoms include weakness or numbness in the face, neck pain, or changes in vision while some patients may experience no symptoms at all.

FMD mostly affects the arteries leading to the kidneys, neck, abdomen and in the extremities. The cause of FMD is not yet known but is debated mostly as a genetic condition. It frequently goes undetected as only a few doctors know how to look for it.

It is often found by accident when people undergo imaging for other conditions, such as stroke. However, if left untreated it can lead to high blood pressure, stroke and aneurysms.

A study conducted by a FMD registry found that 19 percent of the 339 observed patients had suffered a tear in an artery and 17 percent had suffered an aneurysm, or bulging in the artery.

"It's important to diagnose the disease because 20 percent of people who have FMD have an aneurysm somewhere in their body which could leak or burst, a life-threatening condition," said Jeffrey Olin, director of vascular medicine at the Mount Sinai School of Medicine.

The results from the study were presented at the 24th annual International Symposium on Endovascular Therapy (ISET). "Doctors need to look for FMD, particularly in patients younger than 35 who have high blood pressure or migraine-type headaches," Olin added.

Currently,, there are no cures for FMD. But narrowing of the kidney arteries can be treated with angioplasty, where a small balloon is inflated to open up the narrowed artery. Used early enough, angioplasty often can cure the high blood pressure and can prevent stroke.