The build-up of plaque in the inner layer of the wall of an artery may lead to narrowing and irregularity. Where the narrowing is severe, there is a risk that the vessel can block completely if a thrombus (blood clot) forms in the diseased segment.
Reviewed last on: 9/25/2008
Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.