It is estimated that one in four adults (approximately 50 million) in the United States has elevated blood pressure – and more than 30 percent of them are unaware of it. Since people with hypertension may not exhibit any symptoms, their high blood pressure is often undiagnosed until complications occur. It has been proven that blood pressure screening facilitates early diagnosis and treatment. Proper treatment clearly reduces the risk of the complications associated with hypertension.
Blood pressure is the force exerted against artery walls as blood is carried through the circulatory system. The measurement of force is made in relation to the heart's pumping activity, and is measured in millimeters of mercury (mmHg). The higher number, or systolic pressure, is the measurement of pressure that occurs when the ventricle of the heart contracts or beats. The lower number, or diastolic pressure, is the measurement recorded between beats, while the heart is relaxed. The systolic number is placed over the diastolic number and is always the higher of the two numbers. For example, 110/70 (read as 110 over 70).
Elevated blood pressure or hypertension
The diagnosis of hypertension is made when the force required for blood flow is greater than normal. According to the Seventh Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC VII), a blood pressure measurement of less than 120/80 mmHg is considered normal; 120-139/80-89 mmHg should be considered prehypertension; 140-159/90-99 mmHg is stage 1 hypertension; and greater than 160/at or greater than 100 mmHg is stage 2 hypertension. A diagnosis of hypertension is made when a person has had two or more elevated readings after the initial assessment. Readings are taken in a quiet room after relaxation. It is normal for the blood pressure to increase with exertion, or even with pain to a certain extent.
In people over the age of 50, systolic blood pressure (BP) of more than 140 mmHg is a much more important cardiovascular disease (CVD) risk factor than diastolic BP. In fact, the risk of CVD, beginning at 115/75 mmHg, doubles with each increment of 20/10 mmHg. Interestingly, the risk of hypertension increases with age and it has been estimated that despite normal blood pressure at the age of 55 there will still be a 90 percent lifetime risk for developing hypertension.