Overview of High Blood Pressure

Blood pressure is the force of blood in the arteries. When the heart beats, blood propels in the arteries with force. This is called systolic blood pressure. When the heart relaxes after each beat, the force of the blood flow drops (called diastolic blood pressure). Hypertension, or high blood pressure, is the chronic state of elevated pressure in the arteries. A person with systolic and/or diastolic blood pressures consistently above the normal range (120/80 mm Hg) is said to have hypertension.

According to the Centers for Disease Control and Prevention (CDC), one-third of adults in the United States—about 67 million people—have hypertension. High blood pressure is a major risk factor for heart disease, congestive heart failure, stroke, impaired vision, and kidney disease. Generally, the higher the blood pressure, the greater the risk. Untreated hypertension affects all organ systems and can shorten one's life expectancy by 10 to 20 years.

The National Heart, Lung, and Blood Institutes classifies blood pressure as normal, prehypertension, hypertension stage 1, and hypertension stage 2.

Blood pressure readings are expressed as two numbers, such as 140/90 mm Hg. The top number, 140, refers to systolic blood pressure and 90 refers to diastolic blood pressure. Both of these numbers are important.

A study published in Neurology in March 2014 showed that slightly higher than normal blood pressure—even BP classified as prehypertension—can increase stroke risk. More research is needed, but a clinical study involving more than 760,000 people found that people with prehypertension are 66 percent more likely to suffer a stroke than those with normal blood pressure (Low-end prehypertension resulted in a 44 percent increase in risk and people with high-end prehypertensive BP were 95 percent more likely to have a stroke.)

Although medical treatment is not recommended for prehypertension, this research indicates that lifestyle measures to reduce blood pressure—lower-salt diet, weight loss, regular exercise—are important to reduce stroke risk in people with blood pressure that is higher than 120/80. Talk to your health care provider about steps you can take to maintain healthy blood pressure.

Updated by Remedy Health Media

Publication Review By: Jagdish Patel, M.D., F.A.C.C.

Published: 01 Jul 2000

Last Modified: 13 Mar 2014