Helpful Information about Blood Pressure
What is Blood Pressure?
Blood pressure is the force that blood exerts on the arteries. This force is constantly changing
as the heart beats. When the heart contracts, blood pressure reaches its highest value. This
is called systolic blood pressure. When the heart relaxes between beats, the value of blood
pressure is lower. This is called the diastolic blood pressure. The unit of measure for blood
pressure is millimeters of mercury, abbreviated mmHg. For example, an individual's blood
pressure may be measured as 120 mmHg (systolic) and 80 mmHg (diastolic). This would be
spoken as "120 over 80" and written as "120/80".
What Affects Blood Pressure?
Blood pressure can be affected by the following factors: eating, drinking alcohol or
caffeine, smoking, stress, exercise, physiologic condition, measurement site, body position,
temperature, humidity, altitude, and many other factors.
Remember that blood pressure can also vary throughout the day. It is important to take
measurements at the same time each day, and under the same conditions.
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