Sphygmomanometer

A sphygmomanometer is a device used to measure blood pressure. A manometric sphygmomanometer is the old-fashioned blood pressure-measuring device and is the most accurate. When using a manometric sphygmomanometer, a stethoscope is used to hear the sound of blood rushing back through the artery. With a digital sphygmomanometer, the stethoscope is not used.

 

Sphygmomanometer: An Overview

A sphygmomanometer (pronounced sfig'-mo-ma-nom-e-ter) is a device that is used to measure blood pressure.
 

Types of Sphygmomanometers

There are two types of sphygmomanometers:
 
  • Manometric
  • Digital.
     
A manometric sphygmomanometer is the old-fashioned blood pressure-measuring device. It is the more accurate of the two types of sphygmomanometers. A digital sphygmomanometer uses digital readouts. With this type of sphygmomanometer, the blood pressure reading appears on a small screen or is signaled in beeps.
 

Sphygmomanometer: The Device

A sphygmomanometer usually consists of a:
 
  • Pump
  • Dial
  • Cuff
  • Valve.
     

Using a Sphygmomanometer to Measure Blood Pressure

To perform a
 blood pressure test using a manometric sphygmomanometer, a cuff of fabric is wrapped around the arm and then slightly inflated. A stethoscope is used to hear the sound of blood rushing back through the artery. A gauge measures the blood pressure. The healthcare provider reads two numbers from the gauge while air is released from the cuff. The first number is arrived at when a thumping sound is first heard (systolic pressure). The second number is determined when the thumping sound is no longer heard (diastolic pressure). With a digital sphygmomanometer, the stethoscope is not used; instead, the two numbers are generated electronically.
 
The two numbers that represent your blood pressure are written like a fraction: one number on top and one on the bottom. For example, a "normal" blood pressure would be read as 120/80. The number on top refers to systolic pressure. It measures the pressure inside your blood vessels at the moment your heart beats. The number on the bottom is the diastolic pressure reading. It measures the pressure in your blood vessels between heartbeats, when your heart is resting.
 
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD