A digital blood pressure monitor is an instrument used to measure blood pressure by calculating the heart rate and measuring the changes in the arteries as blood flows through them. In contrast to traditional aneroid monitors that require a person to inflate the cuff by squeezing a rubber bulb while listening to a stethoscope and reading a gauge on the monitor to determine blood pressure. Digital versions also contain a cuff that expands and contracts to measure blood pressure, only these modern monitors make that determination automatically, using built-in sensors. Its primarily the ease of use that they provide, that have caused more an more blood pressure monitors to enter the home and serve as useful tools for at home monitoring between doctor’s visits.
Digital blood pressure monitors consist of a cuff that typically wraps around a person’s arm. A pressure-measuring sensor does the work of calculating the wearer's blood pressure, and a screen displays that blood pressure reading. Some models even track blood pressure trends over time, offer paper printouts of blood pressure readings, and store data on multiple users. Rather advanced versions will even send data straight to a doctor’s office via a phone line or Internet connection.
These blood pressure monitors are used in much the same way as traditional monitors. The cuff is wrapped around the arm, just above the elbow joint. Some only work on the left arm, though most will work on either arm. Like traditional tests, the wearer should sit still since even slight movements can result in an inaccurate reading.
After the button that initiates the test is pressed, the cuff on the digital blood pressure monitor will automatically inflate and then once it has fully inflated, it will begin to slowly deflate. A blood pressure reading will then be displayed on the screen. A normal reading is generally 120/80, which is the systolic pressure over the diastolic pressure. High blood pressure is identified at 140/90 or higher, and anything in between is categorized as prehypertension. If the first number — the systolic measure — is below 90, the reading is characterized as low blood pressure, or hypotension.
There are digital blood pressure monitoring systems that wrap around a person’s leg, wrist, or finger, but the ones that wrap around the arm are the most common, and considered to be the most accurate. The wrist monitors are ideal for people who have too much pain in their arms when the cuff inflates, or whose arms are too big for the cuff. The leg monitors typically have a large cuff that can wrap around the thigh.