Standing guard over blood vessel health

Damage to the endothelium sets the stage for cardiovascular disease.

The well-being of your heart and circulatory system depends on a layer of cells half the thickness of Scotch tape that stretches for thousands of miles. This layer, called the endothelium (en-doe-THEE-lee-um), was once thought to be little more than a barrier separating blood from the muscle, nerves, and connective tissue that make up arteries and veins. We now know that it is a dynamic regulator of blood vessel health. Damage to the endothelium, which often begins quietly in childhood, matures decades later as stiff or cholesterol-pocked blood vessels.