The local weather forecast calls for pain increasing over the next five days and tapering off towards the end of the week. Sound familiar? Many people who have arthritis are very familiar this forecast and know that weather effects pain severity. In fact, many people know what the weather is doing just by how a joint feels. Pain, stiffness and swelling can be as accurate at forecasting the weather as a meteorologist. And those who live in certain climates know exactly how painful some climates can be. What do scientists have to say about this weather phenomenon? Are the rumors true? Does joint pain forecast the weather?
Ouch, it's cold outside. Just looking at temperature, one can easily conclude that low temperatures increase pain not only in a joint, but everywhere. Knee pain, rheumatoid pain, and osteoarthritis pain all show consistent increases in severity has the mercury plunges. The reason for this phenomenon probably has something to do with nerve conduction slowing in the cold and soft tissue stiffness in the cold. Just like cars, the human body just does not function well in the cold.
Less obvious than temperature are the barometric pressure changes in the atmosphere that can affect joint pain. These changes are a result of high pressure systems and low pressure systems moving across the earth's atmosphere. For some people, increasing pressure can worsen pain. For others, decreasing pressure worsens pain. Why the difference between low and high pressure? For some, high atmospheric forces pushing in on a joint is painful. For others, internal joint forces pushing out against a lower atmospheric force is painful. The physics may be confusing, but there is no confusing the fact that barometric pressure changes do affect joint pain.
While it may be simple enough to understand how temperature and pressure can worsen pain, it is not so easy to understand why humidity would increase pain. However, those who live in damp areas can experience worsening pain as the humidity rises. Those with rheumatoid arthritis seem to be the most sensitive to higher humidity. Although some scientists recognize the sensitivity to humidity, they question the significance. However, for many people with arthritis joint pain the humidity sensitivity is not only real, but also significant. These folks will tell you, "My bad days are the cold, damp days." In turn, warm, dry days seem to be best for those with joint pain.
Interestingly, various combinations of temperature, barometric pressure, and humidity can all effect individuals in different ways as well. According to one study, temperature and humidity seem to be most associated with osteoarthritis pain. Temperature, pressure and humidity seem to be most associated with rheumatoid arthritis pain. The various combinations and individual differences make the study of this weather phenomenon difficult to study and confirm. But overall, the scientific evidence is fairly consistent; weather does affect joint pain severity.