From the Telegraph….

Researchers found that older people with hypertension suffered a drop in IQ and the ability to recall simple information on days when there blood pressure was particularly high.

While the exact link between high blood pressure and reduced mental ability is unknown, scientists said the research showed that sufferers should be extra vigilant about managing their condition and avoiding stress.

“This means that stressful situations may make it more difficult for some seniors to think clearly,” said Dr Jason Allaire, an assistant professor of psychology at North Carolina State who co-authored the study.

He suggested the effect can be witnessed in people in their 50s, when many people develop high blood pressure and cognitive ability begins to decline.

“If you have high blood pressure it is really important to get it under control.”