UPDATED 2021

The Blood Pressure Test Guide

The Blood Pressure Test Summary
What: Blood pressure tests measure the flow of blood from the heart.
Who: Blood pressure can be checked by a doctor or nurse, or by anyone who learns how to properly take a blood pressure reading.
Where: Blood pressure can be checked in a doctor's office or pharmacy.
When: Everyone should have their blood pressure checked at least once every two years. People with high blood pressure should have it checked more often.
How: Blood pressure tests measure the pressure of blood between heartbeats and during heart contractions.
Type: Manual, automatic and ambulatory
Why: High blood pressure, left untreated, can lead to stroke, heart attack or kidney failure.
Time: Manual and automatic tests take just a few minutes. An ambulatory test measures at intervals through a 24-hour period.
Language: English & Spanish
Preparation: Avoid caffeine and smoking 30 minutes prior to a test. Try relaxing for at least 30 minutes, as well.
Cost: Manual blood pressure testing devices cost between $10 and $300.
High blood pressure is a serious condition that can lead to a heart attack, stroke or kidney failure. High blood pressure is often referred to as a silent killer, as it does not have any symptoms, and many with high blood pressure are not aware that they have it. The only way to detect high blood pressure is to have it tested.

Types of Blood Pressure Tests
There are two common types of blood pressure testing devices. A sphygmomanometer (SFIF’mo-mah-NOM’eh-ter) is a manual testing device, and is typically used in doctors’ offices and homes. A rubber cuff is placed around the upper arm and inflated and a stethoscope is placed on the artery just under the cuff. The air in the cuff is then released and the pulse of blood through the artery can be heard through the stethoscope. The sphygmomanometer gauge provides systolic and diastolic pressure readings. Manual blood pressure testing devices range in price from $10 to more than $200.

Automatic blood pressure testing devices are found in grocery stores, pharmacies and shopping centers. Automatic tests, like manual tests, compress an artery in the arm to momentarily stop the flow of blood. Electronic monitors automatically inflate and deflate with the push of a button and use a microphone to detect blood pulsing in the artery. Some types of monitors can store the results and transfer them to a home computer, while others can relay the information to a doctor over the phone. The accuracy of blood pressure tests found in stores is debatable, so supplementing this with a doctor’s visit or a home test is recommended.

A third type, ambulatory blood pressure monitoring, is not as common, and involves monitoring blood pressure at intervals throughout a one- or two-day period, allowing a doctor to analyze a patient’s average daily blood pressure. A cuff is worn around the arm, while another is worn around the waist.

How Blood Pressure Tests Work
Blood pressure tests measure systolic and diastolic pressure in millimeters of mercury (mm Hg). Systolic blood pressure is the peak blood pressure that occurs when the heart contracts. The measurement is made when the first sound is heard or detected. Diastolic blood pressure is the pressure between heartbeats. This measurement is made when no blood flow is heard or detected.

Blood pressure measurement is presented as systolic pressure over diastolic pressure. For example, if systolic blood pressure is measured at 118 mm Hg and diastolic blood pressure is 79 mm Hg, blood pressure is recorded at 118/79, or 118 over 79.

Blood Pressure Test Results
According to the American Heart Association, a typical adult blood pressure reading is 118/78 mm Hg. While the test demonstrates the ease with which blood flows through the body, readings higher or lower than this average are not always cause for distress. Normal blood pressure is influenced by a many factors, including age, stress, smoking, exercise, pain and noise. Blood pressure also varies depending on the time of day it is taken; pressure tends to be higher in the morning than it is at night. Also, a single high reading does not confirm a high blood pressure problem. Blood pressure should be tested at least once every two years and more often if there is a history of high blood pressure.

Preparation for Testing
When preparing for a blood pressure test, patients are advised to be relaxed, and to avoid exercise, caffeine and tobacco, as well as medicines, such as nasal decongestant spray, for at least 30 minutes prior to the test.

Risks
There are no risks associated with blood pressure tests. A home monitor should be periodically checked by a doctor to ensure that it is working properly.
If you are interested in obtaining a blood pressure monitor for your home or office or in seeing a doctor about high blood pressure, please see our Blood Pressure Test Directory.