An embolus is a blockage of an artery in the lungs by fat, air, tumor tissue, or blood clot.
Review Date 12/4/2015
Updated by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.