Public blood pressure machines, such as those found in pharmacies, may provide helpful information about your blood pressure, but they can have limitations too. The accuracy of these machines depends on several factors, such as a correct cuff size and proper use of the machines. Ask your doctor for advice on using public blood pressure machines.

The blood pressure cuffs on some public blood pressure machines may be too small or too large to get an accurate reading on some people with high blood pressure. Having a properly fitting cuff is important because poorly fitting cuffs don't give accurate blood pressure measurements, which could lead you to think your blood pressure is fine when it's not. An additional concern is that these devices aren't standardized, which makes it hard to know how accurate they are.

It's best to have your blood pressure checked in a medical facility or in a community screening program with trained staff. Before getting a diagnosis of or treatment for high blood pressure, you'll need to have your blood pressure measured by a known, accurate instrument in your doctor's office on several separate visits.

If you need to check your blood pressure more frequently, your doctor can instruct you on the best way to monitor your blood pressure at home, and can check your device for a proper fit and accuracy. Home blood pressure monitoring can be a convenient way to get regular blood pressure readings. But home testing can also have limitations such as a lack of standardization from machine to machine.

Don't stop or change your medications or alter any diet changes you've made without talking to your doctor first, even if your home readings seem normal. Grocery store and pharmacy testing and home blood pressure monitoring aren't substitutes for visits to your doctor.