Manual
28
9.Some Useful Information about Blood Pressure
9. Some Useful Information about 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 140/90, is 
referred to as 140 over 90 mmHg.
HEM-7000 main.book Page 28 Monday, June 19, 2006 8:53 AM










