Since 1913, when a scientist noted that migraines were common in patients with high blood pressure, researchers have tried to establish a link between the two conditions, but studies have shown conflicting results. Now, a study by researchers at the Norwegian University of Science and Technology, in Trondheim, suggests not only that there is no link, but also that high blood pressure seems to reduce the risk of headaches. The findings, published in the Journal of Neurology, Neurosurgery and Psychiatry, are based on the blood pressure readings of more than 22,000 adults who responded to a survey about headache frequency 11 years after their initial reading. Results showed that 28 per cent of participants suffered repeated headaches, of which migraine headaches were reported by one in four. But high blood pressure readings - above 150/90mg Hg - tended to be associated with a 30 per cent lower frequency of headache across all age groups. Furthermore, people with high blood pressure had fewer headaches than people with lower blood pressure readings of 140mg Hg. The higher the reading, the lower the risk of headache, concluded the team. This held true whether or not people had been treated for high blood pressure. Researchers say that one explanation for fewer headaches in people with high blood pressure could be that headache is better treated among these participants because they visit the doctor more often. But a more likely explanation is that high blood pressure reduces pain sensitivity in the brain and spinal cord. This phenomenon, known as "hypertension associated hypalgesia", may explain why there does not appear to be any link between high blood pressure and headache, the team say.
To see more focused health-related content, go to http://www.health-news.co.uk
(c) Health Media Ltd 2002