Next, the valve is opened slightly, allowing the pressure to fall gradually (2 to 3 mmHg per second). As the pressure falls, the level on the dial or mercury tube at which the sound of blood pulsing is first heard is recorded. This is the systolic pressure.
As the air continues to be let out, the sounds will disappear. The point at which the sound disappears is recorded. This is the diastolic pressure (the lowest amount of pressure in the arteries as the heart rests).
The procedure may be performed 2 or more times.
How to prepare for the test
The test may be done at any time with your arm supported and held at the level of your heart. When your doctor needs to compare the current reading to previous ones, the test is usually done after you rest for at least 5 minutes.
All you need to perform a blood pressure measurement is a cuff and a device (stethoscope or microphone) to detect the sound of the pulse in the artery.
How the test will feel
You will feel the pressure of the cuff on your arm. If the test is repeated a few times, you may feel temporary numbness or tingling in your hand.
Why the test is performed
The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends screening adults for high blood pressure every 2 years if their blood pressure is normally less than 120/80 mmHg.
Adults with high blood pressure or prehypertension should have their blood pressure checked every year.
Most people cannot tell if their blood pressure is high because there are usually no symptoms.
High blood pressure increases the risk of
If you have high blood pressure, blood pressure measurements can help determine if your medicine and diet changes are working.
Low blood pressure may be a sign of a variety of illnesses, including heart failure, infection, gland disorders, and dehydration.
