Global study of headaches finds they impact more than 50 percent of people

Headaches can hinder the best of us, and no matter how many times that niggling pain strikes, it's never any less annoying. They can be debilitating, distressing and downright irritating, but the next time you've got a hot pack on your head, remember - you are nowhere near alone.

Headaches are one of the most prevalent and disabling conditions worldwide, and new research has revealed just how prolific the pesky pains are - more than half (52 percent) of the global population is affected by a headache disorder each year. 

International researchers also found 14 percent of those affected by headaches were suffering from migraines, a severe, throbbing pain often accompanied by nausea, vomiting, and extreme sensitivity to light and sound.

The team estimated that 15.8 percent of the world's population have a headache on any given day, with almost half of those individuals reporting a migraine. According to the researchers, all types of headache were more common in females than males, most markedly for migraines (17 percent in females compared to 8.6 percent in males). Females were also more likely to suffer headaches for 15 or more days per month (6 percent in females compared to 2.9 percent in males).

To conduct the study, authors from the Norwegian University of Science and Technology reviewed 357 publications released between 1961 and the end of 2020 to estimate the global prevalence of headaches. The majority of publications considered in the review reported on adults aged between 20 and 65, but some also included adolescents and children aged as young as five and elderly people above 65. 

Building on a report from 2007, lead author Lars Jacob Stovner and his colleagues also measured the differences in methods across the studies they reviewed. They modelled the differences and how they were associated with estimates in headache prevalence. Most studies reported on headache prevalence during the past year. However, some studies reported on headache prevalence across lifetimes and some for much shorter periods, including instances of headache within the last day.

The new review of the evidence, which was published in The Journal of Headache and Pain on Tuesday, concluded that studies of headache prevalence can vary greatly in their methods and samples - which may impact how the global rates of headaches are estimated.

Based on the 357 publications reviewed, the authors estimated that 52 percent of the global population have experienced a headache disorder within a given year, with 14 percent reporting a migraine, 26 percent reporting a tension-type headache and 4.6 percent reporting a headache for 15 or more days per month. 

From the 12 studies that reported on headaches during the last day, the authors estimated that 15.8 percent of the world's population have a headache on any given day, and almost half of those individuals report a migraine (7 percent).

"We found that the prevalence of headache disorders remains high worldwide and the burden of different types may impact many. We should endeavour to reduce this burden through prevention and better treatment," Stovner said following the release of the findings.

"To measure the effect of such efforts, we must be able to monitor prevalence and burden in societies. Our study helps us understand how to improve our methods."

The authors also acknowledged that the majority of publications they reviewed in the study were sourced from high-income nations with good healthcare systems, meaning the findings may not accurately reflect every country worldwide.

Further investigation into middle and low-income countries would help present a more accurate global estimate, Stovner noted. However, to obtain data from as many countries as possible, the authors did use a broad range of studies that sampled participants outside of clinical settings, such as employees, university students and hospital staff, among others.

"Compared to our previous report and global estimates, the data does suggest that headaches and migraine rates may be increasing. However, given that we could explain only 30 percent or less of the variation in headache estimates with the measures we looked at, it would be premature to conclude headaches are definitively increasing," Stovner said.

"What is clear is that overall, headache disorders are highly prevalent worldwide and can be a high burden. It may also be of interest in future to analyse the different causes of headaches that varied across groups to target prevention and treatment more effectively."

The study provides a baseline in how to estimate rates of headaches across the world, the authors noted, and future research could build on this to improve methods for measuring the success of interventions and treatment.