People with painful chronic conditions such as arthritis tend to experience more pain on humid days than on dry ones, according to a British study published Thursday in the journal NPJ Digital Medicine.
When days are windy and have low atmospheric pressure, pain is also more likely to increase, although to a lesser extent than when the humidity is high, the study also reports.
No evidence was found linking cold days with more pain — unless those days were also damp and windy.
“The results of this study could be important for patients in the future for two reasons,” said William Dixon, the lead author of the research and an epidemiologist at the University of Manchester, in a released statement. “Given we can forecast the weather, it may be possible to develop a pain forecast knowing the relationship between weather and pain. This would allow people who suffer from chronic pain to plan their activities, completing harder tasks on days predicted to have lower levels of pain.”
“The dataset will also provide information to scientists interested in understanding the mechanisms of pain, which could ultimately open the door to new treatments,” he adds.
An ancient debate
As Dixon and his co-authors point out in their paper, people with arthritis have blamed weather for worsening their symptoms since at least the fifth century BCE, when the Greek physician Hippocrates was writing his medical treatises. Today, about three-quarters of individuals living with arthritis believe weather affects their pain.
Past studies have investigated these claims, but with conflicting results — most likely because such studies have tended to involve a small number of people (fewer than 100) and/or a short time frame (a month or less).
The current study, according to its authors, is the first to use a large dataset — one collected from smartphones — to look at the relationship between local weather and daily pain among people with chronic conditions over a long period of time.
How the study was done
For the study, Dixon and his colleagues analyzed data collected from 2,658 people, aged 17 and older, from across the United Kingdom. All had a painful, chronic medical condition, such as arthritis, fibromyalgia, migraine or neuropathy. Most, however, had arthritis.
At the start of the study, participants were asked to download a smartphone app, which asked them each evening to answer a series of questions about symptoms they had experienced that day. The participants did so on most days for about six months.
The researchers used the smartphones’ GPS to determine the local weather for each patient on each day. They then looked for correlations between various weather factors and the patients’ reported symptoms.
High humidity had the strongest link with increased pain, although high wind and low atmospheric pressure also showed significant associations.
And when all three of those weather elements occurred together, there was a kind of “pain trifecta,” the data revealed.
“The analysis showed that on damp and windy days with low pressure the chances of experiencing more pain, compared to an average day, was around 20 percent,” says Dixon. “This would mean that, if your chances of a painful day on an average weather day were 5 in 100, they would increase to 6 in 100 on a damp and windy day.”
That may seem like a small increase, but, as Dixon and his colleagues note, it could be a meaningful change for many people living with chronic pain.
The study found no link between temperature alone and pain symptoms.
And although weather is known to affect day-to-day mood and physical activity, those factors were not found to have much of an impact on the study’s findings.
Limitations and implications
The research comes with caveats. Most notably, it involved only people living in the United Kingdom, so its findings may not be applicable to other populations. In addition, the study began with about 10,000 participants, but most failed to complete enough of the daily questionnaires to be included in the final analysis. There may be something different between the people who stayed in the study and those who dropped out — a difference that may make the study’s results less reliable.
Still, the findings are intriguing. They may also offer some reassurance to people who struggle with controlling chronic pain.
“So many people live with chronic pain, affecting their work, family life and their mental health. Even when we’ve followed the best pain management advice, we often still experience daily pain,” says Carolyn Gamble, one of the authors of the study and a graduate student at the University of Manchester, in a released statement. Gamble has a form of arthritis known as ankylosing spondylitis.
“Knowing how the weather impacts on our pain can enable us to accept that the pain is out of our control, it is not something we have done, or could have done differently in our own self-management,” she adds.
FMI: You can read the study in full on NPJ Digital Medicine’s website. The study was funded by Versus Arthritis, a British nonprofit.