i-Kare iBP-130 User Manual page 29

9. Basics of Blood Pressure
What is blood pressure?
Blood pressure is a measure of the force of blood flowing against the walls of the arteries. Arterial
blood pressure is constantly changing during the course of the heart's cycle. The highest pressure
in the cycle is called the Systolic Blood Pressure; the lowest is the Diastolic Blood Pressure. Both
pressure readings, the Systolic and Diastolic, are necessary to enable a doctor to evaluate the
status of a patient's blood pressure.
Why is it a Good Thing to measure Blood Pressure at Home?

Having your blood pressure measured by a doctor can cause anxiety which is itself a
cause of high blood pressure. As a variety of conditions affect blood pressure, a single
measurement may not be sufficient for an accurate diagnosis.

Many factors such as physical activity, anxiety, or the time of day, can influence your
blood pressure. Thus it is best to try and measure your blood pressure at the same
time each day, to get an accurate indication of any changes in blood pressure.

Blood pressure is typically low in the morning and increases from afternoon to evening.
It is lower in the summer and higher in the winter.

Blood pressure is measured in millimetres of mercury (mmHg) and measurements are
written with the systolic pressure before the diastolic e.g. A blood pressure written as
135/85, is referred to as 135 over 85 mmHg.
Classification of Blood Pressure by the World Heath Organization
The World Health Organization (WHO) and the International Society of Hypertension (ISH)
developed the Blood Pressure Classification shown in this figure.
This classification is based on the blood pressure values measured on people in a sitting position
in outpatient departments of hospitals. There is no universally accepted definition of hypotension.
However, those having the systolic pressure below 100 mmHg are assumed as hypotensive.
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