FRIDAY, May 11, 2018 (HealthDay News) -- Mum's the word the next time you have your blood pressure checked.

Talking while the cuff is on can boost your blood pressure reading. So can a full bladder or crossing your legs, the American Heart Association (AHA) says.

"These simple things can make a difference in whether or not a person is classified as having high blood pressure that requires treatment," said Dr. Michael Hochman, a member of the heart association's blood pressure task force. He's also an associate professor of clinical medicine at the University of Southern California.

"Knowing how to measure blood pressure accurately at home, and recognizing mistakes in the physician's office, can help you manage your pressure and avoid unnecessary medication changes," Hochman said in an AHA news release.

Here, the heart association outlines seven common culprits that can alter your blood pressure reading.

• Having a full bladder can add 10 to 15 points to a blood pressure reading. Always try to use the bathroom before getting a reading.
• Poor support for your feet or back while seated can raise your blood pressure reading by 6 to 10 points. You should sit in a chair with your back supported and feet flat on the floor or a footstool.
• Crossing your legs can add 2 to 8 points to your reading.
• If your arm hangs by your side or you must hold it up while getting a reading, your blood pressure numbers may be 10 points higher than the actual figure. Your arm should be on a chair or counter so that the blood pressure cuff is level with your heart.
• Having the cuff placed over clothing can add 5 to 50 points to your reading. The cuff should be on a bare arm.
• A too-small cuff can add 2 to 10 points to a reading.
• Talking can add 10 points to your reading. Remain still and silent while your blood pressure is taken.

More information

The U.S. National Institutes of Health has more on blood pressure.