This is an excellent question and it is one that I face nearly every day in my practice seeing people with arthritis. For now, the best answer I can offer is this: For some people, arthritis pain does seem to increase with low barometric pressure, but others notice just the opposite (higher pressure correlates with more pain) while still others notice no effect. And no one knows why.

Many people with arthritis notice a connection between their symptoms and the weather. Some will notice that joint pain or stiffness seem to worsen when it is about to rain, when the weather is damp and cool or with changes in the barometric pressure. Others will say that any change in the weather makes them feel worse. Still others notice that when they travel to certain climates it seems to improve or worsen their arthritis compared to where they live.

A number of issues make this phenomenon difficult to understand:

• Over the last several decades, studies assessing the effect of weather or barometric pressure on arthritis have yielded inconclusive results. When patients suffering from arthritis were placed in chambers in which temperature, humidity, and barometric pressure were varied, researchers noticed inconsistent effects on joint pain — some preferred higher pressures, others felt better with low pressure, and the rest noticed no effect. Recent studies include the following findings: Arthritic rats appeared to suffer more pain with lowering of the barometric pressure; middle-aged and older people with osteoarthritis noted little or no effect of weather on their joint symptoms; and, among people with osteoarthritis and rheumatoid arthritis who believed strongly that there was a connection between weather and arthritis (half of whom thought they could predict the weather!), analysis of symptoms and weather changes demonstrated little or no effect.
  
  
• There are more than 100 types of arthritis. It is possible that different types of arthritis will respond differently to changes in barometric pressure.
  
  
• Severity of arthritis varies over a wide range. It is possible that mild arthritis will improve in certain circumstances while severe arthritis might respond differently in those same conditions.
  
  
• The relationship between barometric pressure and arthritis may be affected by age, medications and other health issues. For example, some women notice that joint symptoms vary with their menstrual cycle, and joint pain may increase around the time of menopause. Teasing out these factors from changes in weather is not easy.
  
  
• A person's psychological state can affect the perception of pain. Changes in weather or barometric pressure could have an impact on arthritis pain by their effects on psychological health, rather than a direct effect of weather on arthritis.

In my opinion, there is a potentially important message in the connection many people notice between the weather and their arthritis. Understanding this better could lead to improved understanding in why arthritis develops and how better to treat it. However, given how difficult it is to study this connection and the results of studies to date, don't expect a definitive answer to your question anytime soon.