Most patients will have their blood pressure taken whenever they visit a doctor, as this measurement can help the doctor diagnose risk factors for heart disease. Patients may also use machines to test their blood pressure at home. Blood pressure can be measured using cuffs that go around the wrist or the upper arm.
Many patients who use home blood pressure monitors prefer machines that use a wrist cuff. This is because the wrist is often easier to access than the upper arm, and does not require patients to roll up their sleeves or remove their shirt to allow the machine to gain access to the testing site. In addition, wrist blood pressure monitors cause less discomfort during testing.
One factor to consider when using blood pressure monitors is the importance of positioning the arm correctly during testing. If the site being tested is above or below heart level, this will alter the blood pressure reading. Although this is true for both upper arm and the wrist, Family Doctor says that because the wrist is farther from the heart, this can lead to inaccuracies in blood pressure measurement.
Blood pressure monitors that work via the wrist may also be more prone to errors as a result of the anatomy of the wrist, the Mayo Clinic says. The arteries in the wrist are deeper than those in the upper arm, which means they are harder for the monitor to detect. They also are thinner, resulting in a weaker signal. Consequently, even with proper arm positioning, wrist blood pressure measurements are often less accurate than those taken from the upper arm.
Indications For Wrist Blood Pressure Monitoring
Despite the inaccuracies inherent in choosing a wrist blood pressure cuff over one designed for the upper arm, there are instances in which a wrist blood pressure cuff may be needed. Patients who are morbidly obese may not be able to have their upper arm properly fitted to a blood pressure cuff, the Agency for Healthcare Research and Quality notes. They may need to use a wrist blood pressure cuff. Injuries to the upper arm can also make measuring the blood pressure there less feasible.
Blood pressure cuffs for the upper arm and the wrist may both give inaccurate readings if they are not properly calibrated. Although the Mayo Clinic notes that it is easier to check the accuracy of upper arm blood pressure cuffs, patients concerned about the accuracy of their readings should have the results from their home monitor compared with a doctor's office blood pressure readings at both the upper arm and wrist sites.