Higher than normal blood pressure (the force, or tension, of the blood in the walls of the arteries) stresses the heart and can contribute to coronary artery disease, heart attack and stroke. 

High blood pressure (hypertension) is a common condition. Untreated, high blood pressure will cause the heart to eventually overwork itself to the point where serious damage can occur.

It is a major health problem in the United States, where 27 percent of adults have the condition, according to the American Heart Association. An additional 22 percent of Americans, or 45 million, have prehypertension, which is defined as blood pressure that is on the borderline between normal and elevated. Of the people with high blood pressure, 30 percent do not know they have it, and an additional 36 percent either are not on medication or do not have their blood pressure adequately controlled by the medications they do take.