Study: Stroke Risk Up with Prehypertension

Even slightly high blood pressure can increase the risk of stroke, a new review of evidence concludes. The American Heart Association classifies readings above 140/90 as high blood pressure. Below 120/80 is considered normal. The new study looked at the range in between. This is called prehypertension. Researchers put together data from 19 long-term studies. They included a total of 760,000 people. They kept track of people for up to 36 years. Depending on the study, 25% to 54% of people had prehypertension. Nearly 20% of all strokes occurred in this group. The new study also divided this group into 2 different levels of prehypertension. One group had blood pressure readings between 130/85 and 139/89. The other group had blood pressures between 120/80 and 129/84. People in the higher range were 95% more likely to have strokes than those with normal blood pressure.