Unless you know someone who has been diagnosed with an aortic aneurysm, you likely have never heard of the condition. That’s because it causes few noticeable symptoms. Most of the time the diagnosis is the result of an incidental finding from an unrelated exam.

An aneurysm is a ballooning or bulge in the aortic wall that can lead to serious and sometimes life-threatening aortic dissection or hemorrhage. Thomas Maldonado, MD, the Schwartz Buckley Professor of Surgery at NYU Grossman School of Medicine, tells CBS New York, “If an aneurysm ruptures outside the hospital, the vast majority are fatal. If a patient reaches the emergency room with a ruptured aneurysm, 50 percent won’t survive. So it really behooves us to make a quick diagnosis and intervention.”

“They’re called the silent killer for that reason—because they’re silent until all of a sudden they rupture,” says Dr. Maldonado, who is also center director, vascular surgery, of the Center for Complex Aortic Disease. Treating aneurysms early, before they rupture, is crucial for survival, and requires either open surgery or an endovascular approach, in which stents are put in place to prevent the aneurysm from rupturing.

Watch the segment on CBS New York.