There are two main types of blood pressure (BP) monitors: aneroid and digital. Some models measure BP at the wrist or finger, but there's evidence that they aren't as accurate.
Aneroid monitors have a cuff that's inflated by squeezing a rubber bulb, a dial gauge with a needle, and a stethoscope. Your doctor is likely to use this type, and they're typically more accurate. However, they aren't appropriate if you have impaired hearing since you need to listen to your heartbeat through the stethoscope. They also may not suit people with arthritis in their hands, since manual dexterity is required to operate the bulb.
Digital monitors show your BP as numbers on a screen and are available as fully automatic versions with a cuff that inflates at the press of a button or as less expensive semi-automatic versions with a cuff you inflate using a rubber bulb. Some models have a memory that keeps a record of your BP over several months, while some also register an irregular heartbeat. The size of the blood pressure cuff is crucial -- too small a cuff results in a falsely high BP, while too large a cuff results in a falsely low BP. Cuff size depends on arm circumference:
- 8.7 to 10.2 inches: "Small adult" cuff
- 10.6 to 13.4 inches: "Adult" cuff
- 13.8 to 17.3 inches: "Large adult" cuff
- 17.7 to 20.5 inches: "Adult thigh" cuff