Look at the grim statistics the American Heart Association provides on High Blood Pressure

High blood pressure (hypertension) killed 46,765 Americans in 2001. It was listed as a primary or contributing cause of death in about 251,000 U.S. deaths in 2000.
As many as 50 million Americans age 6 and older have high blood pressure.
One in five Americans (and one in four adults) has high blood pressure.
Of those people with high blood pressure, 30 percent don't know they have it.
Of all people with high blood pressure, 11 percent aren't on therapy (special diet or drugs), 25 percent are on inadequate therapy, and 34 percent are on adequate therapy.
The cause of 90'C95 percent of the cases of high blood pressure isn't known; however, high blood pressure is easily detected and usually controllable.
High blood pressure affects more than 40 percent of African Americans.