Headaches and the weather: What does the latest research say?

Many people believe their headaches are directly related to the weather. We explored the connections in this previous article. The verdict: the science so far has not uncovered any mechanisms that would explain how the weather might bring on a headache. Studies have yielded conflicting results and often fail to reflect people’s personal perceptions. So what’s happened in the meantime? Has solid new evidence emerged that sheds light on the mystery?

Big data and AI from Japan – the path to enlightenment?

A major Japanese study from 2023 used artificial intelligence (AI) to investigate the relationship between weather and headache occurrence. The researchers used a smartphone app to collect headache data from a large sample of one million users. This headache data was matched against weather data to identify any patterns. Participants had physician-diagnosed migraine or non-migraine headaches. Big data analytics software supported by AI was used to explore every imaginable correlation. Using headache data collected from 4400 respondents, over 330,000 headache events were screened for links to various weather factors.

Temporal correlation with no conclusive explanation

Time-series data identified trends suggesting a link between weather phenomena and headaches, with low barometric pressure, high humidity, and rainfall seeming to bring on headaches: when these conditions were present, more headache attacks were reported. A drop in barometric pressure before and during attacks was particularly common. These results basically agree with previous research indicating a significant impact of sudden weather shifts. The observations indicate that many people may be exceptionally sensitive to changes in the weather.

However, the detailed mechanisms by which weather contributes to headaches are still unknown. Some studies suggest that factors like humidity, cold, and rainfall can influence headache patterns by affecting the hypothalamus, potentially triggering migraines. However, the authors of this Japanese study emphasize that it is difficult to derive a conclusive hypothesis about the exact mechanisms involved in signal processing up to the onset of an attack.

More research needed

A study by Hungarian researchers in 2023 reviewed existing research on weather and headaches, concluding that differences in the design of the various studies make it challenging to draw consistent conclusions. The researchers concur with the conclusions of the authors of the Japanese study, noting that no study has definitively shown which mechanisms determine how our bodies respond to weather conditions.

Is geomagnetism a potential headache trigger?

Some studies hypothesize that geomagnetic activity affects the body in ways that could act as triggers for headache disorders. However, all these speculations lack an explanation of how exactly this might happen. Quite simply, no organs or brain areas have been found with this sort of interaction, such as the interaction between our sensory organs and the stimuli that they perceive and process.

Barometric pressure, ambient temperature and headaches: which mechanisms do we know about?

Some of the research explored in the Hungarian study looks at barometric pressure, as discussed in relation to the Japanese study. Environmental temperature also features repeatedly as a possible factor, though conclusive evidence is lacking. Nevertheless, we do at least have evidence showing that the function of certain nerve pathways – such as those around joints – is influenced by temperature and pressure conditions. Research in animals has also found that air pressure can influence pain sensitivity in certain models of neurological pain. However, scientists are still not clear on how these individual findings fit into the complex picture of headache disorders.

Does the weather affect inflammatory processes in our bodies?

Another line of inquiry looks at the inflammatory processes thought to be involved in causing migraines. Fluctuations in ambient temperature, pressure and humidity could fire up the production of inflammatory substances and activation of immune cells, potentially leading to localized inflammation that is painful in itself or contributes to triggering a migraine. A related hypothesis proposes that the known weather variables might affect brain regions believed to be involved in pain perception and processing. These areas also influence cognitive and emotional states and are involved in overall mood regulation, pain sensitivity, and triggering periods of depression.

Just looking at the numerous individual observations on how weather affects our bodies, it’s clear that coming up with a cohesive explanation is likely to be quite a challenge. Even now, much pioneering work remains to be done in this area.

Are perceptions truths? A psychological analysis

A 2023 US study took a different approach to the weather-headache connection, questioning whether the perceived subjective link between weather and headaches is genuinely rooted in personal experience or actually due to other reasons.  

On a score from 0 to 100%, 300 participants were asked to rate the likelihood that exposure to certain triggers – including weather events – would bring on a headache. The responses revealed a widespread and consistent belief that weather phenomena were headache triggers. However, more in-depth inquiries by the research team showed that participants’ assumptions about a triggering effect were based more on persistent hearsay and subjective impressions than personal experience – which was comparatively rare.

Personal experience versus learned beliefs

The theory that the weather can be a potent trigger for headaches of various kinds seems to be so ingrained across all sections of the population that it overshadows actual lived experience. The authors speculate that as we go through life, we learn in ways that significantly shape how plausible we find certain triggers in our personal perceptions. These intrinsic couplings, formed through learning or handed down as “facts,” seem to be effective and active all the time, regardless of how often an individual has actually experienced them on a personal level.

The study concludes that beliefs learned within a societal and family context underlie the notion that weather events trigger headaches. Many people seem to have entrenched ideas and beliefs based to a large extent on hearsay or assumptions without ever having personally observed or experienced an actual cause-effect relationship.

More explanation needed

Combining findings from different research methods and taking into account important psychological factors, like the recent study did, it's clear that there's still no solid proof linking certain weather conditions to the headaches people experience. While some correlations are based on solid evidence, research so far has not been able to explain the underlying physiological mechanisms. This intriguing field offers ample opportunity for further research, potentially yielding valuable insights for headache prevention.