Slightly raised blood pressure can increase stroke risk

American data suggests at least 10 per cent of people have a blood pressure that is above normal but does not qualify as “high”.

The researchers found that in groups whose average age was 65 or under, having a blood pressure between “normal” and “high” was linked to a 79 per cent higher risk.

In someone whose general risk of stroke is very low this will have a very small impact, but it could be serious in people whose risk is already higher than normal.

Writing in the Neurology journal, the researchers said young and middle aged people with slightly high blood pressure should consider cutting down their salt intake and exercising more to reduce their risk.

Dr. Bruce Ovbiagele of the University of California San Diego in America, said: “At this point it is way too early to recommend blood pressure drugs”, but recommended eating less salt, having a healthy body size and exercising well.

One study focused on older patients found that the same blood pressure levels did not raise the chance of stroke, most likely because old age is such a significant risk factor in itself.

Blood pressure is recorded in two measurements known as systolic and diastolic, with anything consistently lower than 130 millimetres of mercury (mmHg) systolic or 80mmHg diastolic considered “normal”.

High blood pressure, or hypertension, is classified as consistently higher than 140/90mmHg, but the new study showed that having a measurement in between the two could also have a significant health impact.

Dr Sharlin Ahmed of The Stroke Association said: “Forty per cent of all strokes could be prevented if people took steps to control their blood pressure.

“A small increase in blood pressure could lead to high blood pressure in the future, so it’s very important to have regular checks.”

Maureen Talbot of the British Heart Foundation added: “This interesting study supports what we already know, which is the importance of keeping our blood pressure under control whatever our age.

“If a blood pressure reading is borderline, losing some weight and exercising more can often be enough to get things back to normal.”