One of the first things you do when you visit the doctor's office is get your blood pressure measured. A blood pressure reading can tell you a lot about your current health and whether or not you're at high risk for stroke, heart attack, kidney failure or heart failure.

But chances are, your health care provider isn’t even taking your blood pressure the right way.

That's according to Paul Whelton, a cardiovascular specialist at the Tulane University School of Public Health, who told NPR that there are several rules medical professionals are supposed to follow and they aren't taking enough care to do so.

For example, Whelton said, you’re supposed to sit in silence for five minutes before having your blood pressure measured.

You’re also not supposed to exercise or have caffeine within 30 minutes of your test.

Those are just a couple of the commonly undervalued rules that can lead to inaccurate blood pressure readings.

And small inaccuracies in blood pressure measurement can have major consequences.

"It has been predicted that the consequences of an untreated 5 mm Hg of excessive systolic blood pressure would be a 25 percent increase over current levels of fatal strokes and fatal myocardial infarctions for these individuals," Dr. Joel Handler of Kaiser Permanente wrote in a 2009 study about the importance of an accurate blood pressure measurement.

Overestimating blood pressure readings can also lead to inappropriate treatment, exposing patients to “adverse drug effects, the psychological effects of misdiagnosis, and unnecessary cost,” Handler wrote.

To address the issue of inaccurate readings, Whelton and his colleagues rolled out a checklist for medical professionals to follow when taking a patient’s blood pressure.

Here are the do’s and don’ts from a patient’s perspective, Whelton told NPR:

Before the test:

Do empty your bladder before having your blood pressure taken.

Don't exercise, smoke or consume caffeine within 30 minutes of your test

During the test:

Do sit in a chair with your feet flat on the ground, your legs uncrossed with your back supported and without talking, for at least five minutes before your test.

Do roll up your sleeves so the blood pressure cuff rests on your skin and not your clothing.

Don't have your blood pressure taken while sitting or lying on the exam table.

Don't let your arm dangle or rest in your lap during the blood pressure reading.

After the test:

If your blood pressure seems high, do get a reading in both arms.

The next time you come in, do get a reading in the arm that showed the higher blood pressure.

The American Heart Association last week announced new guidelines that lowered the threshold for high blood pressure, adding 30 million U.S. adults to the bucket of those with a condition that now affects nearly half of the American adult population.

For decades, high blood pressure was determined with a top reading of at least 140 or a bottom one of 90. Now, according to the new guidelines, a reading of 130/80 is considered high pressure, a change that adds 30 million U.S. adults to the bucket of those with the condition.