Did you get a headache at the weekend? If so, scientists think they know why – it was the weather.
A rise in temperature or a fall in barometric pressure, which often accompanies a thunderstorm, may trigger a headache or migraine. After a cold spell last week the temperature rose to 13.8C in London on Saturday, more than 5C warmer than on Thursday – explaining why some people found themselves in pain. Headache sufferers have long suspected that changes in weather can trigger an attack.
Now they have scientific backing for their claims from one of the largest studies of the link. Researchers who monitored 7,000 patients with headaches serious enough to make them seek treatment at a hospital A&E department found the main trigger was a rise in temperature in the previous 24 hours.
The risk of a severe headache rose by 7.5 per cent for every 5C rise in temperature. Falls in barometric pressure in the previous 48 to 72 hours also had an effect, though to a lesser extent. But other effects such as humidity and air pollution had no impact, the findings revealed.
The results of the study, by scientists at the Beth Israel Deaconess Medical Centre in Boston, in the United States, help put a piece of clinical folklore on an evidential base. But they do not explain the link, or what mechanism may lie behind it.
Kenneth Mukamal, who led the study published in Neurology, said: "Our results are consistent with the idea that severe headaches can be triggered by external factors. These findings tell us that the environment around us does affect our health and, in terms of headaches, may be impacting many, many people.