DALLAS (AP) _ Nearly a third of American adults have high blood pressure, putting them at greater risk of stroke, heart attack, kidney failure and other problems, according to a new government analysis.
The obesity epidemic and an aging population are to blame, experts say. Just over a decade ago, closer to one in four Americans had high blood pressure, and two decades ago the rate actually was declining.
About 65 million American adults now have high blood pressure _ 30 percent more than the 50 million who did in the previous decade, according to a report published Monday in Hypertension: Journal of the American Heart Association.
``The big message to the American public on that is that we need to pay attention to our lifestyle and those that are overweight need to get slimmer,'' said Dr. Daniel Jones, dean of the School of Medicine for the University of Mississippi Medical Center and an expert on high blood pressure.
The study didn't examine reasons for the blood pressure spike, but experts said the fact the population is getting older and fatter probably plays a major role.
``It's not surprising because we've seen that Americans are getting fatter, and we know that blood pressure goes up when people gain weight,'' said Dr. David Goff, an epidemiology expert at Wake Forest University School of Medicine in North Carolina, who was not involved in the analysis, which involved Census Bureau and other health statistics.
The risk of hypertension, or high blood pressure, is increased by old age, excess weight and lack of physical activity. A standard blood pressure reading is given as systolic pressure over diastolic pressure. Systolic, the larger of the two numbers, should ideally be below 120, while the diastolic number should be under 80.
The study found that at least 65 million Americans either have blood pressure in the high range, take blood-pressure lowering medicines or have been told at least twice that they had high blood pressure.
High blood pressure adds to the workload of the heart and arteries. Over time it can mean the heart and arteries do not work as well as they should.
The condition can be treated with medicine and lifestyle changes, including eating less fat and more fruits and vegetables, becoming more physically active and limiting salt intake.
The new figures are from Census data and a 1999-2000 National Health and Nutrition Examination Survey, which included 4,531 adults. It estimates that 31.3 percent of Americans have high blood pressure, up from 28.9 percent in the previous national health report from 1988-94.
Dr. Jeffrey Cutler, senior scientific adviser at the National Heart, Lung and Blood Institute, said that between 1980 and 1990 the prevalence of high blood pressure was decreasing, but that was before the obesity surge of the late 1980s.
Four out of 10 black Americans have high blood pressure, compared with about three out of 10 Mexican Americans and whites.
``It's clear we're not paying enough attention to the things that can prevent and manage high blood pressures,'' Jones said.
There are no symptoms of high blood pressure. ``That's why they refer to it as the silent killer,'' said Dr. Larry E. Fields, lead author of the study and an adviser to the U.S. assistant secretary for health. So he said healthy adults should be checked at least every two years.
Only two out of three people who have high blood pressure know that they do, and only one in three has the condition under control.