It is best to keep blood pressure at normal (120/80 mmHg). Better still, there is a benefit in keeping blood pressure as low as possible.High blood pressure is generally defined as a reading above 140/90 mm Hg and, if untreated, it raises the risk of stroke and heart attack. It's becoming increasingly clear that these figures don't represent a clear cut-off point below which there's no health risk. Research is now focussing upon the high normal or borderline group, with blood pressure of less than 140/90 but more than 130/85.
Generally research studies show that people who have high normal blood pressure have an increased risk of death from heart attack or stroke, compared to those with optimal - 120/80 or low blood pressure. An ongoing study reveals that borderline blood pressure also increases the risk of non-fatal cardiovascular events.
The researchers, Boston University, studied nearly men and women, dividing them into three groups on the basis of blood pressure: borderline and optimal, as defined above, and an in-between group defined as normal where blood pressure lay between 130 and 120 (top figure) and 70 and 80 (bottom figure). Over the 12 years following initial blood pressure measurement, rates of cardiovascular events were1.5 per cent, 2.2 per cent and 4.1 per cent for women depending on whether blood pressure was optimal, normal or borderline. The figures for men were: 5.1 per cent, 6 per cent and 10 per cent.