I. Cuff Selection and Preparation
1. Choose the appropriate size: The cuff bladder width should cover 40%-80% of the upper arm circumference. A standard adult cuff is suitable for an upper arm circumference of 22-32cm. A cuff that is too narrow or too wide will result in a reading that is too high or too low. If the arm circumference is unusual (e.g., in children or obese individuals), a special cuff must be used.
2. Check the cuff condition: Before use, ensure there is no residual air inside the cuff and check that the bladder, tubing, and buckle are intact to avoid leaks affecting the measurement.
II. Correct cuff wearing method
1. Positioning: Place the lower edge of the cuff (edge of the bladder) 2-3 cm above the elbow crease, ensuring the center of the bladder is aligned with the brachial artery (the inner side of the upper arm where you can feel a pulsation).
2. Adjust the tightness: The cuff should be tight enough to easily insert 1-2 fingers. Too tight a cuff can compress blood vessels, leading to a lower reading; too loose a cuff may lead to a higher reading.
3. Fixation Method: Wrap the cuff smoothly around your upper arm, avoiding twisting or wrinkles, then fasten the buckle to ensure a snug fit without compressing the skin.
III. Measurement Posture
1. Arm Position: During measurement, the arm (along with the cuff) must be at the same level as the heart. When measuring while seated, the arm should rest naturally on the table; when measuring while lying down, the arm should rest flat at the sides of the body.
2. Body Posture: Maintain an upright sitting posture, with your back against the chair and both feet flat on the ground. Avoid talking, moving, or crossing your legs during the measurement.
IV. Common Mistakes and Precautions
1. Cuff Position Too High or Too Low: A cuff positioned too high (close to the shoulder) is likely to result in a lower reading; a cuff positioned too low (close to the elbow) is likely to result in a higher reading.
2. Cuff Too Tight or Too Loose: This is one of the most common sources of error in home self-testing.
3. Preparation before measurement: Sit quietly for at least 5 minutes before measurement, avoiding exercise, smoking, or immediate measurement after drinking coffee or strong tea.
V. Summary of Cuff Wearing Steps
1. Choose the right cuff: Select the appropriate size cuff according to your arm circumference.
2. Eliminate air: Ensure there is no residual air inside the cuff before use.
3. Position and wrap: The lower edge should be 2-3 cm from the elbow crease, with the air bladder aligned with the brachial artery.
4. Adjust the tightness: The tightness should allow for the insertion of 1-2 fingers.
5. Fix the arm: Keep the arm at heart level and stationary.
