Are blood pressure machines in grocery and drug stores accurate
"Not accurate enough to make health decisions regarding your blood pressure," explains Douglas Marquess, MD, who practices internal medicine at Baptist Medical Associates.
The blood pressure machines that you can use free of charge in many grocery stores and drug stores may have been accurate when first installed. But in order to stay accurate, they must be maintained and recalibrated. Generally, no information is available regarding the care of these devices. As a result, the reading you get has limited value because it may be incorrect. That’s why there’s a notice next to them saying "not for diagnostic purposes."
In addition, the blood pressure cuffs on these do-it-yourself machines are often too small to get an accurate reading on a significant number of people with high blood pressure. These machines have a standard size cuff, and if your arm is too big or too small for the cuff, you’ll get an incorrect reading. To ensure accuracy, the inflatable portion of the cuff should cover at least 80 percent of the upper arm.
"It’s best to have your blood pressure checked in a medical facility or in a community screening program with trained staff. If you need to check your blood pressure more frequently, your doctor can instruct you on the best way to monitor your blood pressure from home. If you have no other access to getting your pressure checked, you can use these machines for following the trend of your blood pressure," Dr. Marquess adds.