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What Those Blood Pressure Numbers Mean

A quick, painless test measures blood pressure. A rubber cuff is wrapped around your arm and inflated. The cuff compresses an artery in your arm and momentarily stops your blood flow. A technician uses a stethoscope to measure your blood pressure when the pressure in the cuff is released.

If you are checking your blood pressure at home, here are some tips to help you take an accurate blood pressure:

• Make sure the blood pressure cuff fits your arm properly. The cuff should be long enough to fit around your arm with several inches extra. It should be wide enough to fit from the inside of the elbow to just below the armpit, according to the American Medical Association (AMA). Measuring the distance from your shoulder to your elbow. If the distance is less than 13 inches, you need a small cuff (5 inches by 9 inches). If the distance is 13 to 16 inches, you need a medium cuff (6 inches by 13 inches). If the distance is more than 16 inches, you need a large cuff (7 inches by 14 inches). An arrow on the cuff helps you align the cuff over an artery.
• Keep in mind that blood pressure fluctuates during the day and depending on what you are doing. It often is higher in the morning. Your blood pressure also may be higher if you have been talking or if you are under stress.
• Your blood pressure may be slightly lower at home than when it is measured by your health care provider. Your doctor may ask you to take your blood pressure several times a day.
• If you smoke or drink caffeinated beverages, these can affect your blood pressure for two or more hours afterward.
• Talk to your doctor about the type of blood pressure monitor you need. Electronic versions may be convenient, but they are not as accurate as a blood pressure cuff (sphygmomanometer).