Many people notice that their bodies ache or feel stiff when rainy weather approaches. This common observation has a scientific basis rooted in how atmospheric changes interact with the human body. The sensation of pain coinciding with weather shifts is a phenomenon researchers continue to explore.
The Barometric Pressure Connection
Barometric pressure, also known as atmospheric pressure, measures the weight exerted by air molecules at a specific location on Earth. This pressure is influenced by factors like air temperature and density, with colder, denser air typically leading to higher pressure and warmer, lighter air to lower pressure. A standard barometric pressure at sea level is approximately 29.92 inches of mercury (1,013 millibars), though this can vary.
Before or during rainy weather, barometric pressure often drops. This decrease in atmospheric pressure signals the approach of a low-pressure system, frequently associated with clouds and precipitation. This change in external pressure creates an imbalance with the relatively stable pressure inside the human body.
How Pressure Changes Affect the Body
When external barometric pressure drops, there is less force pushing against the body, allowing tissues and fluids to expand slightly. This subtle expansion can increase pressure on surrounding nerves, potentially leading to pain or discomfort. In particular, areas with enclosed spaces, such as joints containing synovial fluid, can be affected.
The fluid within joints may expand or become thicker when pressure changes, contributing to stiffness and pain. This expansion can also stretch inflamed tissues or exacerbate pre-existing conditions.
Who is Most Affected?
While everyone experiences barometric pressure changes, some individuals are more sensitive to the associated body aches. People with arthritis, including osteoarthritis and rheumatoid arthritis, often report increased joint pain during weather shifts. In osteoarthritis, where cartilage is worn away, exposed nerve endings may become sensitive to these pressure changes. For those with rheumatoid arthritis, the inflammatory nature of the condition may make joints more reactive to environmental triggers.
Individuals with fibromyalgia often report heightened pain, fatigue, and stiffness during weather changes, particularly before storms. This is thought to be due to their central nervous system’s increased sensitivity, which can amplify the body’s response to barometric fluctuations. Old injuries, such as fractured bones or sprains, can also ache with changes in pressure. Scar tissue formed from past injuries may become less pliable, and the expansion of tissues around the injury site can irritate nerves, leading to pain perception.