Taking A Blood Pressure Measurement; Before The Measurement; Common Sources Of Error - ReliOn BP200W Instruction Manual

5. Taking a blood pressure measurement

Please note: You should always be seated before and during the
measurement.

5.1. Before the measurement:

• Avoid eating, smoking as well as all forms of exertion directly before
your measurement. These factors influence the measurement result.
Relax by sitting in an armchair in a quiet atmosphere for about ten
minutes before your measurement.
• Always measure on the same wrist (normally left).
• Compare readings at the same time of day, since your blood pressure
changes during the course of the day.

5.2. Common sources of error

Note:
Comparable blood pressure measurements always require the
same conditions. These are normally always quiet conditions.
• All efforts to support the arm can increase blood pressure. Make sure
you are in a comfortable, relaxed position and do not flex any of the
muscles in the measurement arm during the measurement. Use a
cushion for support if necessary.
• If the wrist artery lies considerably lower (higher) than the heart, an
erroneously higher (lower) blood pressure will be measured. (Each 15
cm/6" difference in height results in a measurement error of 10 mmHg.)
• A loose cuff causes false measurement values.
• With repeated measurements, blood can accumulate in the respective
arm, which can lead to false results. Correctly executed blood pres-
sure measurements should therefore first be repeated after a 1
minute pause or after the arm has been held up in order to allow the
accumulated blood to flow away.
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