Hypertension is the medical term for high blood pressure. Blood
pressure is the force of blood flow against the artery walls.
Blood pressure measurements are read as two numbers. The higher
number, called the systolic pressure, represents the pressure in
the artery when the heart beats. The lower number, called the
diastolic pressure, represents the pressure when the heart is at
rest. Normal blood pressure is in the range of 120/80. High
blood pressure, or hypertension, is defined as systolic pressure
greater than 140 and/or diastolic pressure greater than 90.
Blood pressure fluctuates throughout each day. In most cases,
the cause of hypertension is unknown. Genetic factors may be
involved. In addition, the following conditions may cause
hypertension: narrowing of the arteries, excess fluid in the
blood, stronger than normal heartbeats, certain medications, or
disorders of the kidneys, nervous system, or endocrine system
(hormones). According to the American Heart Association, about
73 million Americans have