It may not produce any symptoms, but high blood pressure puts you at risk for serious health problems, including stroke, heart disease, and kidney failure. Authors of a study recently published in the Journal of the American Medical Association estimate that as many as 9 in 10 Americans are at risk of developing high blood pressure at some point in their lives.

About the study

Researchers from the National Heart, Lung, and Blood Institute's Framingham Heart Study studied 1298 people enrolled in the Framingham Heart Study—a larger study of 5209 men and women aged 28 to 62 who did not have cardiovascular disease when the study began in 1948. Framingham participants have undergone a complete medical exam with medical history and lab tests for cardiovascular risk factors (such as high blood pressure) every two years since their enrollment.

This smaller study followed 1298 men and women who were aged 55 to 65 and did not have high blood pressure when they were examined in 1975. The researchers followed these participants from 1976 through 1998 and tracked the number of people who developed high blood pressure.

The researchers monitored several measures of high blood pressure, including blood pressure readings at the biennial exams, use of blood pressure-lowering medications, and severity of high blood pressure. The threshold for high blood pressure was 140/90 mmHg. Blood pressure higher than 140/90 but lower than 160/100 was considered stage one high blood pressure. Blood pressure of 160/100 or higher was considered stage two high blood pressure.

The findings

The lifetime risk of developing high blood pressure in this group was 90%. This means that 9 in every 10 people will probably develop high blood pressure over a lifetime. In addition, the lifetime risk of developing stage two high blood pressure or taking blood pressure-lowering drugs was 70%. This lower percentage is probably due to the fact that people with stage one high blood pressure who make lifestyle changes or begin taking medication are not likely to develop stage two high blood pressure.

The study authors explain that the 90% risk of developing any degree of high blood pressure likely represents the upper limit of our risk. And the 70% risk of developing stage two high blood pressure or needing to take blood pressure-lowering drugs represents the lower limit of our risk. Either way, the risk is quite high.

There are several limitations to this study, however. First, most of the study subjects were white so these results may not apply to people of other racial and ethnic groups. Second, blood pressure readings were single readings from each biennial exam rather than averages of several readings taken on separate occasions. This may have overestimated the risk of high blood pressure. However, this study did not include people who developed high blood pressure before age 55, a factor that may have underestimated high blood pressure risk. Finally, this study did not examine any of the factors that increase your risk of high blood pressure, such as obesity, family history of high blood pressure, dietary sodium and potassium intake, smoking, and alcohol consumption.

How does this affect you?

Does this mean that everyone has to worry about high blood pressure? Worrying about it won't do much good, but there are a number of things you can do to keep your blood pressure in a healthy range. Normal blood pressure is 130/85 or lower, but blood pressure of 120/80 or lower is ideal. If you already have high blood pressure, you should be seeing your health care provider regularly and you may need to take medication. If your blood pressure is in the normal range, the Journal of the American Medical Association offers the following advice on how to keep it there:

  • See your health care provider regularly and have your blood pressure checked.
  • Don't smoke cigarettes or use illegal drugs.
  • Lose weight if you are overweight.
  • Eat a healthful diet that is low in salt and saturated fat.
  • Exercise regularly. Check with your health care provider before beginning an exercise routine for the first time.
  • Limit alcohol intake to one drink per day for women and two drinks per day for men.