According to the Centers for Disease Control and Prevention, approximately 50 million adults in the United States have high blood pressure, but because there are often no symptoms, many people don't realize they have it unless it develops into a more serious condition such as heart disease or stroke, the first and third leading causes of death in the U.S. This is why it is important for people with moderate to high blood pressure to monitor their levels on a regular basis.
Blood pressure machines in stores throughout the community offer convenience and affordability to the person monitoring his blood pressure. However, the accuracy of these machines is open to debate. Individuals should bear a few precautions in mind before relying on store blood pressure machines as part of their health care regimen.
Understanding Blood Pressure
It's not uncommon for people to rely completely on their health care providers to monitor their blood pressure without really understanding it themselves. It is always advisable to arm oneself with as much information as possible, and this is particularly true for the individual planning to monitor her blood pressure independently using machines in stores.
Blood pressure is the force of blood against the artery walls as blood circulates through the body. It is measured using an inflatable cuff attached to a gauge. The cuff is wrapped around the arm and inflated; as it is deflated, the pulse in the arm can be heard using a stethoscope and the blood pressure is read on the gauge. It is important that the cuff be placed at the level of the heart and wrapped around a bare arm for an accurate reading.
Blood pressure is measured using two numbers: systolic and diastolic. Systolic, the top number, represents the pressure against the artery walls when the heart beats. Diastolic, the bottom number, represents the pressure between heartbeats, or when the heart is at rest. If, for example, systolic pressure is 120 and diastolic pressure is 80, we would say that blood pressure is 120 over 80.
Normal blood pressure is considered to be less than 120 over 80. Individuals with systolic pressure between 120 and 139 and diastolic pressure between 80 and 89 are considered to be at risk for developing high blood pressure, and those with blood pressure greater than 140 over 90 are considered to have high blood pressure.
Controlling the Environment
Environment has a significant impact on a blood pressure reading. A reading taken in a calm environment is likely to be lower than a reading taken in a stressful environment--such as a typical store--so care should be taken to control the environment to the extent possible when having blood pressure measured.
First, the individual should check the store at various times of the day to identify the least busiest time. This should become his regular time for blood pressure checks. Next, he should avoid coffee and smoking for 30 minutes prior to the measurement. Finally, he should sit and rest for five minutes before measuring his blood pressure.
Significance of Cuff Size
An accurate blood pressure reading is dependent upon using the proper blood pressure cuff size. For a proper fit, the inflatable portion of the cuff should cover at least 80 percent of the arm without overlapping. Using a cuff that is too small will result in a reading that is lower than the actual level; conversely, using a cuff that is too large will result in a reading that is higher than the actual level. For these reasons, health care providers change blood pressure cuffs to fit each individual in order to maximize accuracy. Unfortunately, blood pressure machines in stores do not have this capability; they use the same size cuff for everyone. Because two-thirds of all adults in the U.S. are overweight, only one-third of all blood pressure readings on store machines will be accurate.
Knowing When to Seek Care
It is essential that the individual using a store blood pressure machine keep a meticulous record of readings to identify patterns and recognize when to call his health care provider. Dr. Max Reif of the University of Cincinnati recommends that three readings should actually be obtained each day--each one minute apart. If the third reading is substantially different than the first two, obtain an additional reading for verification. View the results as an average in determining whether or not a problem may exist.
The purpose of keeping a record is twofold: first, of course, it records the actual readings; but secondly, and more importantly, it allows a comparison of readings from one week to the next. Some machines may not get calibrated after the first day they are put in service; consequently, they may not be very accurate. In this case, the blood pressure reading itself will be less important than the comparison of blood pressure readings for changes.
If the record reflects a pattern of hypertension, or high blood pressure, the individual should see his health care provider for an assessment of his condition. Just as importantly, if he notices an increase in either systolic or diastolic that remains elevated he should also seek care.
Recommendations
Blood pressure machines in stores do have drawbacks--they tend to be located in noisy environments, they are generally available only with one cuff size and they may not be entirely accurate. Yet the advantages they offer--convenience and affordability--make them an option that should not be overlooked. Understanding blood pressure and the effects of a cuff size too large or small, controlling the environment and maintaining a record of blood pressure readings are all important steps toward getting the most out of store blood pressure machines.
References
- Net Wellness: Drug Store Blood Pressure Machines
- Journal of Family Practice: The Accuracy of Community-Based Automated Blood Pressure Machines
- Mayo Clinic: High Blood Pressure (Hypertension)
- Centers for Disease Control and Prevention: High Blood Pressure
- Centers for Disease Control and Prevention: Obesity and Overweight
