If the cuff is wrong size, it could give a reading that is too high or too low.
To avoid this, the air bladder inside the cuff should fit around at least 80% of the arm but not more than 100%.
If the cuff is not big enough, and less than 80% of the arm is covered by the air bladder, then the cuff may not be able to completely close off the blood vessels. In this case, the bladder will inflate too much and the monitor will give a higher reading than it should.
If the cuff is is too large, and the air bladder in the cuff overlaps (covers more than 100% of the arm), then the cuff will inflate on itself. This means that it will cut off the blood supply too easily and the monitor will give a lower reading than it should.
Take a piece of string and measure around your upper arm at the midpoint between your shoulder and elbow. Then choose your cuff size from the table below:
|Monitor cuff sizes|
|Measurement (cm)||Measurement (inches)||Cuff size|
|17-22 cm||6.75 - 8.75"||Small|
|22-32 cm||8.75 - 12.5"||Medium|
|32-42 cm||12.5 - 16.5"||Large|
All Blood Pressure Association monitors come with the choice of a medium cuff or a large cuff. Please choose the right size for you when ordering.