The cuff should always feel comfortable. If you measure your own blood pressure at home, make sure you are using the correct cuff size.
What is it?
During the measurement of your blood pressure, a soft cuff is placed around your bare upper arm. Inside the cuff is a rubbery inflatable bag, often called a bladder. This cuff is then inflated gently to interrupt the bloodflow in your artery. When the cuff is deflated, blood flows again and can be heard with a stethoscope or recorded by an electronic device. This depends on the type of measurement tool used.
Size is crucial
In either case, to get a reliable reading, the correct cuff size is essential. Most sphygmomanometers have three different cuff sizes: one for thin arms, one for thicker arms and one for the thickest arms. 80 % of the inflatable bladder inside the cuff should encircle the arm.
If an undersized cuff is used, the blood pressure can be overestimated by 10 – 25 mm Hg. Since many hypertensive patients carry excess weight, a larger cuff should always be at hand. Incorrect measurement has health and cost implications.
(Dr Kathleen Coetzee, MBChB)