Omron Bloodpressure Monitor

Monitoring blood pressure levels at home or work with a home blood pressure monitoring device may help determine a person's true range of blood pressure readings and avoid false readings from the white coat hypertension effect.

Omron HEM-780 Automatic Blood Pressure Monitor with ComFit Cuff

Aside from the white coat effect, bloodpressure readings outside of a clinical setting are usually slightly lower in the majority of people. The studies that looked into the risks from hypertension and the benefits of lowering the blood pressure in affected patients were based on readings in a clinical environment.

Basic digital blood pressure monitors are relatively inexpensive.

Making it easy for patients to monitor their own blood pressure. Their accuracy can vary greatly; most have not been certified for accuracy by an approved authority. Upper arm, rather than wrist, monitors usually give readings closer to auscultatory. Some meters are automatic, with pumps to inflate the cuff without squeezing a bulb.

The auscultatory method uses a stethoscope and a sphygmomanometer. This comprises an inflatable (Riva-Rocci) cuff placed around the upper arm at roughly the same vertical height as the heart, attached to a mercury or aneroid manometer. The mercury manometer, considered to be the gold standard for blood pressure measurement, measures the height of a column of mercury, giving an absolute result without need for calibration, and consequently not subject to the errors and drift of calibration which affect other methods.

The use of mercury manometers is often required in clinical trials and for the clinical measurement of hypertension in high risk patients, including pregnant women.

A cuff of appropriate size is fitted and inflated manually by repeatedly squeezing a rubber bulb until the artery is completely occluded. Listening with the stethoscope to the brachial artery at the elbow, the examiner slowly releases the pressure in the cuff.

When blood just starts to flow in the artery, a "whooshing" or pounding sound (first Korotkoff sounds) is heard. The pressure at which this sound is first heard is the systolic blood pressure. The cuff pressure is further released until no sound can be heard (fifth Korotkoff sound), at the diastolic blood pressure. Sometimes, the pressure is palpated (felt by hand) to get an estimate before auscultation. With a mercury manometer this is simple technology which gives accurate pressure readings without issues of calibration.