The coronary arteries supply blood to the heart muscle itself. Damage to or blockage of a coronary artery can result in injury to the heart. Normally, blood flows through a coronary artery unimpeded. However, a process called atherosclerosis can cause a buildup of cholesterol and cells and other substances in the wall of the artery forming a plaque. If this process restricts blood flow enough it may result in a lack of oxygen to the heart muscle and cause angina. If the inner wall of a coronary artery becomes damaged, the inner contents of plaque can be exposed to the bloodstream and the body can bring substances such as platelets to the injured site and cause a further narrowing or complete blockage.
If blood flow is reduced severely or completely, death of part of the heart muscle that the artery supplies can occur. This is called a heart attack.
Review Date 5/10/2019
Updated by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.