New guidelines are lowering the threshold for high blood pressure diagnoses, adding 30 million Americans to those who have the condition, which now plagues nearly half of U.S. adults.

High blood pressure, which for decades has been a top reading of at least 140 or a bottom one of 90, drops to 130 over 80 in advice announced Monday by a dozen medical groups.

 

The change means an additional 14 percent of U.S. adults have the problem, but only 2 percent need medication right away; the rest should try healthier lifestyles, which get stronger emphasis in the new advice. Poor diets, lack of exercise and other bad habits cause 90 percent of high blood pressure.

“I have no doubt there will be controversy. I’m sure there will be people saying, ‘We have a hard enough time getting to 140,'” said Dr. Paul Whelton, a Tulane University physician who led the guidelines panel.

But the risk for heart disease, stroke and other problems drops as blood pressure improves, and the new advice “is more honest” about how many people have a problem, he said.

Now only half of Americans with high blood pressure have it under control.

The upper threshold for high blood pressure has been 140 since 1993, but a major study two years ago found heart risks were much lower in people who aimed for 120. Canada and Australia lowered their cutoff to that; Europe is still at 140 but is due to revise its guidance next year.

The guidelines were announced Monday at an American Heart Association conference in Anaheim.

WHAT THE CHANGES MEAN

The guidelines set new categories and get rid of “prehypertension”:

» Normal: Under 120 over 80

» Elevated: Top number 120-129 and bottom less than 80

» Stage 1: Top of 130-139 or bottom of 80-89

» Stage 2: Top at least 140 or bottom at least 90

That means 46 percent of U.S. adults have high pressure (stages 1 or 2) versus 32 percent under the old levels.

For people over 65, the guidelines undo a controversial tweak made three years ago to relax standards and not start medicines unless the top number was over 150. Now, everyone that old should be treated if the top number is over 130 unless they’re too frail or have conditions that make it unwise.

HOW AND WHEN TO CHECK IT

Blood pressure should be checked at least once a year by a health professional, and diagnosing high pressure requires two or three readings on at least two occasions.

The common way uses a cuff on the upper arm to temporarily block the flow of blood in an artery in the arm and gradually release it while listening with a stethoscope and counting sounds the blood makes as it flows through the artery. But that is prone to error, and many places now use automated devices.

The guidelines don’t pick a method, but recommend measuring pressure in the upper arm; devices that work on fingers or are worn on wrists “aren’t ready for prime time,” Whelton said.

 

AP