What is a blood pressure Machine called?
Or a large error may be introduced. Is improper blood pressure cuff size a common error? You bet it is. You may need a large cuff if your arm size is 11 or 12 inches. By 13 inches you do need a large cuff.
First, what is a blood pressure cuff? An essential part of measuring a blood pressure is the compression of the artery so that no blood flows through. The operator then listens to the sounds of the blood being pushed through as the compression is gradually reduced. An inflatable bladder encased in a cloth sleeve, which is wrapped around the upper arm, accomplishes the compression. This part is called the cuff. Its critical characteristic is its size.
The error that is introduced by too small a blood pressure cuff is a reading that is too high and the error can be 50 mm and this is not rare. Just think of it as the little cuff having to work much too hard to compress the artery and thus generates an artificially elevated reading. This can lead to incorrect diagnosis and/or excess treatment.
Too large a cuff introduces the opposite error, an artificially low reading but not nearly the magnitude of the too small cuff error.
How to measure your arm: Using a flexible cloth (not metal) tape, measure the circumference of your upper right arm about the middle. This is in inches or centimeters and it's a good idea to know both. Memorize it.
This is just one way your reading can be falsely elevated. Another source of fairly large error is the false elevation occurring when someone else takes your blood pressure This is called White-coat Hypertension and is discussed more on the