Is there a link between pain and the weather? Many people who live with chronic pain would say a resounding “Yes.” In terms of scientific evidence, however, the answers to this question could be conflicting. Perhaps some of the limitations to studying the relationship between weather and severe pain include the unpredictability of the weather and the need for consistent self-reported data on the part of the person living with pain. Technology is facilitating the way toward more robust evidence about how the weather affects pain. In particular, Cloudy with a Chance of Pain (“Cloudy”) is an ongoing mobile-based study that aims to explore and understand the relationship between pain and the weather.
Weather-related pain reports
Many people who suffer from some form of chronic pain report that the weather in some way affects the severity of their pain. Physicians admit that patients often complain about muscle, joint, or nerve pain because of changes in temperature or a surge of coldness. According to Dr. Stephen Humble, a consultant at the London Pain Clinic, “A significant majority of patients with chronic pain report that their symptoms are aggravated by changes in the weather. Generally, it is cold, damp weather that has the most impact, however, patients can also mention other weather conditions having an impact.”
Another physician, Dr. Zbigniew Kirkor, a consultant in anesthesia and pain medicine who runs the Pain Clinic at the Princess Royal Hospital in Telford, Shropshire, UK, says, “In my clinic, patients often say that when they traveled to Spain or the South of France [or generally moving from a colder to a warmer area of Europe], their pain was better.”
Some evidence of the pain-weather relationship does exist, although some findings are conflicting and limited only to one type of pain, osteoarthritis. A 2007 study provides evidence of a link between pain severity among people with osteoarthritis and changes in barometric pressure (the weight of the surrounding atmosphere) and ambient temperature (the temperature of the air in the surrounding environment). In a 2012 study, pain levels were found to increase as barometric pressure increased day to day. No relationship between pain and temperature and precipitation (water vapor such as rain or snow), however, was observed.
Most of these reports are anecdotal, especially accounts of patients living with chronic pain who say their pain can effectively predict a change in the weather. The explanations as to why there’s pain during weather changes are also mostly still hypothetical. As a result, some people are reluctant to talk about their weather-related pain to family members or even practitioners for fear of being ridiculed.
The cloudy project
According to William Dixon, professor of digital epidemiology at the University of Manchester’s School of Biological Sciences and scientific lead for the Cloudy project, “Problems can occur when people don’t believe patients — including a breakdown in relationships. Clarifying that there is a [pain-weather] link might help patients provide the evidence that their suggested link is indeed true.”
Launched by the University of Manchester in 2016, Cloudy is a national smartphone-based study that aims to investigate the association between pain and weather. According to Louise Cook, project manager of the study, “The scope of this project is to establish whether there is a relationship between weather and pain and, if so, what that relationship is. We will look at the range of chronic pain conditions reported by our participants against weather variables captured by local weather stations.”
Participants in the study are living with arthritis and/or chronic pain. Funded by Arthritis Research UK, the project provides members of the public with a special application on which they can track their pain symptoms daily. Using the participant’s smartphone Global Positioning System (GPS), data about the local weather conditions are automatically captured and corresponded with the symptom data reported by the participant. Approximately 9,000 people in the UK alone have participated in the study during its first six months, which has generated over 2.5 million pieces of data.
Given the remote nature of data capture in the study design, the project can involve people from a range of temperatures and climates all over the world and thus is also the world’s first smartphone-based study that can explore in detail the weather-pain link.
Based on preliminary results, there does seem to be a link between the number of sunny days and levels of precipitation and changes in pain severity. Specifically, the data analyzed in this interim review were captured from participants residing in three UK cities — Leeds, Norwich, and London.
Between February and April 2016, the researchers found that as the number of sunny days increased (almost doubling), the length of time during which participants experienced severe pain markedly decreased. However, as participants entered the summer season in June, which had slightly fewer sunny days than April and more rainfall that led to a warmer and wetter climate, participants across the three cities reported increased incidents of severe or very severe pain. Interestingly, London participants reported the highest pain severity during June. Of the three cities, London experienced the warmest temperatures but the fewest number of sunny days in June.
Explanations for the pain-weather link
With the opportunity to involve participants throughout the four seasonal changes, the Cloudy study can begin to shed light on what exactly causes pain severity for a range of chronic pain conditions in relationship to changes in the weather. Currently, there are several theories, but no proven mechanisms.
As Humble states, “I’m not aware of any specific scientific research [into the pain-weather link explanation] and so feel that the relationship at present is best described as uncertain.” It is clear, however, that people suffering from chronic pain have altered bodily interpretations of coldness and hotness. “In a proportion of patients with neuropathic pain (nerve pain), the thermal thresholds of the nerves can be altered (i.e., an average person may start to feel heat-related pain or discomfort at 50 degrees Celsius, but for a person with neuropathic pain, the temperature threshold to experience pain or discomfort may be lower),” explains Humble. Furthermore, he says, “People with hypersensitivity to cold due to neuropathic pain are unable to keep their hand submerged in a bucket of iced water for as long as the average person — this is referred to as the ‘Cold Pressor Test.’”
Kirkor adds, “As for the nerve pain, often, a cold environment makes the neuropathic pain worse. People with trigeminal neuralgia [severe facial pain] experience pain attacks when exposed to cold or blowing wind. And patients with fibromyalgia [chronic pain condition affecting muscles and soft tissue] generally do not tolerate cold and feel better in a warm environment.”
Nonetheless, experts do attempt to explain the pain-weather link. Some experts believe changes in atmospheric pressure also create pressure on the joints and push the synovial fluid (the fluid that reduces friction between cartilages) toward the subchondral bone (the bone layer beneath the cartilage in a weight-bearing joint), impacting some nerve endings. Other experts consider pain severity a chemical reaction to the change in weather, whereby the change in atmospheric pressure induces immune cells to produce inflammatory responses, which can cause or exacerbate feelings of physical pain. Some experts believe that the perceived link between pain and the weather is potentially psychological in nature.
As Kirkor reveals, some of his patients report experiencing less severe pain when moving to sunnier parts of Europe. “The relation here may be twofold: a) warm, dry weather is better for arthritic joints; and b) people in nice weather generally feel better and are less depressed, relaxed, and in a better mood, and it makes their pain more bearable,” he explains.
Implications of the Cloudy project
The initial results from the Cloudy study suggest that pain severity is associated with changes in sunshine, temperature, and rainfall. Such findings do not yet provide a clear explanation as to what exactly causes or influences pain. However, the study opens the door to several beneficial implications for chronic pain sufferers and the prescription and development of their treatments. While the study is based in the UK, the results could also have global implications for people living with severe pain.
The findings could serve as a catalyst for the development of new interventions to target specific types of chronic pain conditions. Cook says, “We hope that other researchers will use the findings to establish why weather affects pain and to develop suitable treatments.” Researchers can delve deep into the rich data from thousands of participants living with a range of chronic pain types and examine how the pain-weather association could differ across various types or causes of chronic pain.
Potentially, findings could also influence the attitude of some physicians toward patients’ concerns or queries about the impact of seasonal or climate changes on their conditions. It remains the duty of physicians to ensure that chronic pain patients are given the most appropriate medicines based on the needs associated with their condition. “Clinicians should ensure that patients have been trialed on drugs that are not standard painkillers, but are specific for neuropathic pain,” says Humble.
If a weather-pain link is established, Kirkor believes that “Doctors should inform their patients about it, but it is difficult to predict how physician prescription will change once the complete findings from the Cloudy study are available. Personally, I think that not much will change. This is something that will remain in the area of self-management, like dieting and physical activity.”
Cook agrees, explaining that evidence of the weather-pain link will be an opportunity for patients to better manage their pain condition. “Many people are looking for evidence to vindicate their view that their pain is affected by weather and this recognition will be of value to them. Once people know if and how their condition is affected by weather, it will help them self-manage, as they can tailor certain activities to days when they feel their pain will be less severe,” she says.
Dixon adds, “Patients tell us that a prediction of when their pain will flare would allow them to manage their activities. For example, if they had a large task to do during the week, they might do this in advance of the predicted flare.”
Pain self-management amid the weather
How can people better manage their pain knowing that there is a chance the weather could affect the severity of their pain? According to Kirkor, “As I used to say to my patients, I am unable to offer them a hot sun on prescription, but they can manage by moving to warmer environments when possible. People with trigeminal neuralgia usually prefer to stay indoors during cold and windy periods. Fibromyalgia patients often like to swim, but they do not tolerate cold water in normal public swimming pools and choose warmer ones commonly used for hydrotherapy.”
Humble comments, “People living with chronic pain could move to a country with a different climate. They could wrap up warmer than usual. In addition, they could ask to have higher doses of their medication to cover them over certain times of the year and then reduce the dosages during the good times to minimize the chance of becoming tolerant to medications.” He adds that some patients respond well to prescription topical menthol cream that helps desensitize joints. Generally, people suffering from chronic pain must keep the change in weather in mind by wearing protective clothing, stretching and loosening the joints, using heating/cooling pads or creams, and staying mobile to keep warm and prevent any swelling.
The interim findings of the Cloudy study are very promising, but the researchers are keen to gather more robust data. As Dixon reveals, “We haven’t yet performed a formal analysis of this [pain-weather] relationship. This will only come after the end of the data collection period next year.” In the meantime, many researchers and people living with pain are eager for the final results.