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Your Guide to Lowering Blood Pressure NHLBI Logo

High Blood


Stethoscope - A stethoscope is used to hear the sound of the blood rushing back through the artery.  The first thumping sound is the systolic blood pressure.  When the thumping sound is no longer heard, that's the diastolic pressure. Valve - A valve lets some air out of the cuff, which allows the blood flow to start again. Cuff - A cuff is wrapped around your upper arm. Pump - a pump inflates the cuff to stop the blood flow in your artery for a few seconds. Dial - A numbered dial or column of mercury can be used to record the blood pressure reading.

How Is Blood Pressure Tested?

Having your blood pressure tested is quick and easy. Blood pressure is measured in millimeters of mercury (mmHg) and recorded as two numbers systolic pressure "over" diastolic pressure. For example, the doctor or nurse might say "130 over 80" as a blood pressure reading.

Both numbers in a blood pressure reading are important. As we grow older, systolic blood pressure is especially important.

To test your blood pressure, your doctor will use a familiar device with a long name. It is called a sphygmomanometer (pronounced sfig’-mo-ma-nom-e-ter), and may look something like this:

Picture of sphygmomanometer and stethoscope

Some blood pressure testing devices use electronic instruments or digital readouts. In these cases, the blood pressure reading appears on a small screen or is signaled in beeps, and no stethoscope is used.

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