What Is It?

Blood pressure has two components:

• Systolic pressure, the higher number, represents the pressure the heart generates to pump blood to the rest of the body.

• Diastolic pressure, the lower number, refers to the pressure in the blood vessels between heartbeats.

Usually, systolic pressure increases as we age. However, after age 60, diastolic pressure usually begins to decline because the body's blood vessels stiffen.

Blood pressure is measured in millimeters of mercury (mmHg). Normal blood pressure is defined as a systolic pressure of less than 120 and a diastolic pressure of less than 80. People with a systolic blood pressure between 120 and 139 or a diastolic blood pressure between 80 and 89 are said to have prehypertension. High blood pressure, or hypertension, is divided into two stages:

• Stage 1 hypertension - Systolic blood pressure between 140 and 159 and/or diastolic blood pressure between 90 and 99

• Stage 2 hypertension - Systolic blood pressure greater than 160 and/or distolic blood pressure greater than 100.

High blood pressure can cause damage to many organs, including the brain, eyes, heart and kidneys, as well as to arteries throughout the body. If you have high blood pressure that has not been diagnosed, or that is not being treated adequately, you are at greater risk of having a heart attack, stroke, and kidney failure.

Symptoms

In general, high blood pressure does not directly cause symptoms. When blood pressure is very high, it can cause symptoms such as headaches, dizziness, fatigue and ringing in the ears. However, it often causes no symptoms.