IF YOU are struck down with chronic headaches, it might be to do with the weather, new research suggests.
SCIENTISTS have confirmed a link between lightning and headaches and migraines.
A study found that lightning striking up to 40km away can increase the risk of headache by 31pc while thunderbolts also led to a 28pc increased risk of migraine attacks.
US researchers looked at 90 chronic headache sufferers with an average age of 44.
All had conditions that fulfilled the criteria for migraines as defined by the International Headache Society.
Participants recorded their headache experiences in a daily journal for three to six months.
During this time, scientists recorded lightning strikes within 40km of people's homes. The magnitude and polarity of the current was also measured.
Geoffrey Martin, from the University of Cincinnati, who co-led the research, said: "Many studies show conflicting findings on how weather, including elements like barometric pressure and humidity, affect the onset of headaches.
"However, this study very clearly shows a correlation between lightning, associated meteorological factors and headaches."
Mr Martin conducted the study with his father Vincent, a professor of internal medicine at the University of Cincinnati and a headache expert.
Prof Martin said there were a number of ways in which lightning might trigger headaches.
He said: "Electromagnetic waves emitted from lightning could trigger headaches. Lightning produces increases in air pollutants like ozone and can cause release of fungal spores that might lead to migraine."
The research, published in the International Headache Society online journal Cephalalgia, showed that negatively charged lightning currents were associated with headaches.
When the scientists adjusted their results to take account of other weather factors linked to thunderstorms, they still found a 19pc increased risk of headaches on lightning days.
"This suggests that lightning has its own unique effect on headache," said Prof Martin.
"The effect of weather on headache is complex, and future studies will be needed to define the role of lightning and thunderstorms on headache."