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.
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.