The Pain Forecast

The Pain Forecast

Do you worry about pain when you wake up on a gloomy day? Then you’re not alone. A lot of people believe the weather has an impact on pain, and this idea has been around since ancient times. Now there is also scientific evidence for a relationship between certain weather conditions and pain.

Scientists in the UK have together with RA patients developed a smartphone app for logging pain, and involved members of the public in a citizen science project to investigate pain in relation to the weather.

Cloudy with a chance of pain

Three quarters of people living with chronic pain, and 80% of people living with RA, believe their pain is affected by the weather (1, 2). Some say pain gets worse on damp and rainy days, others that pain gets worse by the cold, and yet others report that warm humid days are the worst. Fifty percent even believe painful joints can predict weather changes.

A research group at the University of Manchester, headed by William Dixon, Professor of Digital Epidemiology, wanted to find out if there was any scientific evidence behind these beliefs, something that has been difficult to prove in the past despite several efforts (3). So, they conducted a large study, where they digitally followed 13,000 people living with chronic pain over 15 months. Their study is called Cloudy with a Chance of Pain (4).

Study participants could log their pain intensity daily using a smartphone app. This information was then linked to local weather data, via the GPS location of the phone. The researchers received 5.1 million pain reports in total, which were then analyzed by comparing the weather on days of high pain intensity with days of no pain. They had enough data points for the final analysis to be performed on nearly 3000 of the study participants, with an average age of 51 years, of which 83% were women. 

The study shows what we have known for years

In line with many people’s beliefs, the study could indeed associate higher humidity, lower atmospheric pressure and stronger winds—in that order—to higher pain intensity. On the other hand, temperature and rain did not seem to influence pain. Combining the worst weather conditions increased the risk of pain by 20% compared to an average day.

It is important to remember that weather can also affect a person’s mood and degree of physical activity, two factors which in turn may influence pain. Yet, the study could show that mood and physical activity did not explain the association found between weather and pain. At the same time, mood was—independent of the weather—strongly linked to pain, while physical activity had a more modest impact.

It is also possible that people’s prior beliefs of a weather-pain relationship could affect the results in this type of study. But this does not seem to be the case, as most people believed that rain and cold would cause pain, which the study could not show, and a pain-humidity relationship was found in all study participants, irrespective of their prior beliefs.

Why is this important knowledge?

The study acknowledges what people have believed for more than two thousand years (5), that pain can be affected by the weather. The effect found in the study was modest, but still statistically significant and could be valuable information for people living with chronic pain.

When asked whether one could avoid pain by staying in on “bad” weather days, Will Dixon says: “Some elements of weather (such as wind and rainfall) can be avoided by staying inside. However, others like pressure are similar when indoors compared to outdoors. [Still,] if you know that certain weather might increase your pain, you can plan your activities around it and do more burdensome activities on days when your pain might be lower” (6). 

The Cloudy with a Chance of Pain study gives no explanation for the association between weather and pain, but it emphasizes the importance of understanding how and why pain is influenced by the weather, and that more research is needed in this area. A deeper understanding of pain mechanisms could lead to the development of better treatments for people living with chronic pain.

With more and more of us being digitally connected, the study also highlights the huge opportunities that come with research in digital epidemiology. There are still many unanswered questions­­—about how health is related to environment and lifestyle—that can now be addressed using smartphones. Such knowledge could empower us to take control of our lives.

References

  1. Hagglund et al. Weather, beliefs about weather, and disease severity among patients with fibromyalgia. Arthritis Care Res. 1994, 7(3):130-5.

  2. Timmermans et al. Self-perceived weather sensitivity and joint pain in older people with osteoarthritis in six European countries: Results from the European Project on OSteoArthritis (EPOSA). BMC Musculoskelet. Disord. 2014, 5;15:66.

  3. Smedslund and Hagen. Does rain really cause pain? A systematic review of the associations between weather factors and severity of pain in people with rheumatoid arthritis. Eur. J. Pain. 2011, 15(1):5–10.

  4. Dixon et al. How the weather affects the pain of citizen scientists using a smartphone app. NPJ Digit Med 2019, 24;2:105.

  5. Hippocrates. On Airs, Waters and Places. http://classics.mit.edu/Hippocrates/airwatpl.html (400 B.C.E.).

  6. https://www.cloudywithachanceofpain.com/the-project