National Institutes of Health
National Institute of Neurological Disorders and Stroke website
Main Getting Started Teacher's Guide Student Activities About NIH and NINDS
The following is drawn from materials from the American Heart Association (www.heart.org/HEARTORG) and the National Heart, Lung, and Blood Institute (www.nhlbi.nih.gov/health/public/heart/index.htm).
What is hypertension?
Hypertension, or high blood pressure, is defined in an adult as a blood pressure
greater than, or equal to, 140 mm Hg systolic pressure or greater than or
equal to 90 mm Hg diastolic pressure. Hypertension does not refer to being
tense, nervous, or hyperactive. Optimal blood pressure for an adult is 120
mm Hg systolic and 80 mm Hg diastolic. Blood pressures are normally written
as systolic/diastolic, such as 120/80.
Cause:
In most cases, the cause of high blood pressure is unknown. This type of high
blood pressure is called essential hypertension.
In the remaining cases (5%–10% of cases), high blood pressure, called secondary
hypertension, is a result of another health problem such as a kidney abnormality,
tumor of the adrenal gland, or congenital defect of the aorta. Blood pressure
usually returns to normal when the underlying cause is corrected.
Symptoms and diagnosis:
Diagnosis of high blood pressure is based on the average of two or more readings
taken at each of two or more visits after an initial screening.
Hypertension usually has no symptoms. Many people have high blood pressure and don’t know it. If hypertension is severe, symptoms may include:
Treatment:
The prescribed treatment depends on the severity of hypertension, but may
involve the following components:
Long-term consequences of uncontrolled hypertension:
High blood pressure directly increases the risk of coronary heart disease
(which leads to heart attack) and stroke, especially along with other risk
factors. Uncontrolled hypertension can also lead to renal failure.
Long-term outlook for hypertension if treated and
controlled:
Hypertension is controllable with treatment, which may require periodic adjustment.