Hypertension, also known simply as "high blood pressure" is very common, however can lead to many significant complications if left uncontrolled. When the blood pressure is elevated, the force the blood puts on the walls of the arteries is high and can lead to artery damage. Also, when the heart muscle has to pump blood against a high blood pressure, it thickens and enlarges, just like any muscle does when it has to do more work (think of a weight lifter).
Hypertension develops slowly over the years and frequently does not cause any symptoms until something severe happens such as a heart attack, stroke or heart failure. Fortunately, hypertension is easily diagnosed and treated to help prevent this from happening.