Feature Archive

High Blood Pressure: The Invisible Health Risk

It has no symptoms, but kills 50,000 Americans a year.

By Gina Shaw
WebMD Feature

Reviewed By Charlotte Grayson

It's 2005: Do you know what your blood pressure should be? Within the last two years, a number of new studies have led doctors to rethink their conclusions about what defines high blood pressure (hint: it's lower than you think), and the best approaches to treating this deceptively symptom-free disease.

More than 50 million Americans aged 6 and older now have high blood pressure, also called hypertension. Only one in three is keeping their blood pressure under control with medication, lifestyle measures, or both. You could be one of them and not even know it: 30% of people with hypertension have no idea they have it.

High blood pressure is easy to ignore, because it has no symptoms other than numbers on a blood pressure cuff. But its silence is deadly. Hypertension killed nearly 50,000 Americans in 2001, and the rates continue to rise, according to the American Heart Association. Uncontrolled high blood pressure puts you at risk of heart attack, stroke, heart failure, kidney disease, and a host of other problems.

Think You're Safe? Check Again

Within the last two years, we've learned that blood pressure levels we once thought were "safe" may not be. "We used to say that risky blood pressure levels didn't begin until around 140/90, but it's now become clear from more recent studies that the risk probably begins somewhere between 115 to 120 over 75 to 80," says Elijah Saunders MD, professor of medicine and head of the section of hypertension in the division of cardiology at the University of Maryland School of Medicine in Baltimore. "So we now use 120/80 as a round figure for where risk begins."

Doctors have coined the term "prehypertension" to describe people whose blood pressure is above 120/80, but not yet at 140/90. "We believe these people are at higher risk, and studies show that they do have lots of the same hypertension complications that we thought didn't occur until blood pressure was much higher," Saunders says.

Recent studies funded by the Agency for Health Care Research and Quality estimate that as many as two-thirds of people between the ages of 45 and 64 might have prehypertension. That the rate is significantly higher for those 65 and over. If you have other complicating conditions -- particularly diabetes and kidney problems -- along with prehypertension, doctors now recommend treating your blood pressure aggressively with drugs to help lower your risk of heart attack or stroke.

What if only the top number is high? That's your systolic pressure, and research now shows us that it's more important in determining whether or not you have hypertension. If your systolic pressure is high but your diastolic pressure is normal, you still have hypertension and you're still at risk. "High systolic pressure is a very powerful risk factor for cardiovascular complications," says Saunders. "It's also responsible for most uncontrolled hypertension."

Change Your Blood Pressure, Change Your Life

We don't know exactly what causes high blood pressure, although we do know that family history plays a role. You can't do anything about your genes, or about getting older, or about being black -- all added risk factors for hypertension (hypertension affects about 40% of the black population, and it's more likely to show up earlier in life and be more severe than in whites). But you're also not doing yourself any favors if your pantry is stocked with potato chips and other salty treats, if you drink too much alcohol, and if the last time you worked up a sweat was in anticipation of the Survivor finale.

The good news: all that can be changed. One of the best ways to control hypertension is -- surprise! -- with healthy diet and exercise, the same things that help to prevent so many other diseases and disorders.

The gold standard of hypertension eating plans is the DASH diet (Dietary Approaches to Stop Hypertension), endorsed by the National Heart, Lung, and Blood Institute and clinically proven to reduce blood pressure. This low-fat diet calls for:

  • 7-8 servings a day of high-fiber grains
  • 4-5 servings a day of fruits
  • 4-5 servings a day of vegetables
  • 3 servings a day of low-fat dairy
  • 2 or fewer servings a day of meat, poultry, or fish
  • 4-5 servings a week of beans, nuts, or seeds