Blood Pressure Measurement

• Cuff – A cuff is wrapped around your upper arm.
• Pump – A pump inflates the cuff to stop the blood flow in your artery for a few seconds.
• Valve –A valve lets some air out of the cuff, which allows the blood flow to start again.
• Stethoscope – A stethoscope is used to hear the sound of blood rushing back through the artery. The first thumping sound is the systolic blood pressure. When the thumping sound is no longer heard, that’s the diastolic pressure.
• Dial – A numbered dial or a column of mercury can be used to record the blood pressure reading.

Some blood pressure testing devices use electronic instruments or digital readouts. In these cases, the blood pressure reading appears on a small screen or is signaled in beeps, and no stethoscope is used.

Blood pressure readings are usually taken when you are sitting or lying down and relaxed. Below are things you can do before going to get your blood pressure taken:

• Don't drink coffee or smoke cigarettes 30 minutes before having your blood pressure measured.
• Before the test, sit for five minutes with your back supported and your feet flat on the ground. Rest your arm on a table at the level of your heart.
• Wear short sleeves so your arm is exposed.
• Go to the bathroom prior to the reading. A full bladder can change your blood pressure reading.
• Get two readings, taken at least two minutes apart, and average the results.

Ask the doctor or nurse to tell you the blood pressure reading in numbers.

Self Measurement of Blood Pressure

You also can check your blood pressure at home with a home blood pressure monitor. Blood pressure self measurements may benefit patients by providing information on response to antihypertensive medication, improving patient adherence with therapy, and in evaluating white-coat hypertension. Persons with an average blood pressure more than 135/85 mmHg measured at home are generally considered to be hypertensive.

Home measurement devices should be checked regularly for accuracy. It is important that you understand how to use the monitor properly. Your doctor, nurse, or pharmacist can help you check the monitor and teach you how to use it correctly. You also may ask for their help in choosing the right blood pressure monitor for you. Blood pressure monitors can be bought at discount chain stores and pharmacies. Below are additional things to do when taking your blood pressure at home:

• Sit with your back supported and your feet flat on the floor.
• Rest your arm on a table at the level of your heart.
• Take two readings, at least 2 minutes apart, and average the results.

Ambulatory Blood Pressure Monitor

Another way to check blood pressure away from the doctor's office is by using an ambulatory blood pressure monitor. Ambulatory blood pressure monitoring (ABPM) provides information about blood pressure during daily activities and sleep. ABPM is warranted for evaluation of “white-coat” hypertension in the absence of target organ injury. It is also helpful to assess patients with apparent drug resistance, hypotensive symptoms with antihypertensive medications, episodic hypertension, and autonomic dysfunction.

The ambulatory blood pressure values are usually lower than clinic readings. Awake, individuals with hypertension have an average blood pressure of more than 135/85 mmHg and during sleep, more than 120/75 mmHg. The level of blood pressure measurement by using ABPM correlates better than office measurements with target organ injury.18 ABPM also provides a measure of the percentage of blood pressure readings that are elevated, the overall blood pressure load, and the extent of blood pressure reduction during sleep. In most individuals, blood pressure decreases by 10 to 20 percent during the night; those in whom such reductions are not present are at increased risk for cardiovascular events.