Knee pain is a symptom frequently associated with the development of rheumatoid arthritis and osteoarthritis. Individuals with these disorders sometimes report increases or decreases in their pain levels that appear to be associated with changes in local weather conditions. While studies of these weather-related symptoms produce conflicting results, knee pain in these circumstances may stem from changes in temperature, relative humidity or barometric pressure.
Barometric pressure is a measurement of the density of air particles in the atmosphere, according to Scholastic.com. In warm weather, relatively few particles occupy a given area of space. In cool weather, particle density increases, and more air particles occupy the same area. Humidity is a measurement of air's moisture content. If you live in a high-humidity environment, the air in your locale contains more moisture than the air in a low-humidity environment. Relative humidity measures the current amount of moisture in the air in relation to the maximum possible moisture content.
Osteoarthritis is a degenerative disease of your joints that causes pain and stiffness, according to the Centers for Disease Control and Prevention. It triggers destruction of your cartilage and associated bone, in addition to causing abnormal new bone growth. Rheumatoid arthritis is an autoimmune disease that causes inflammation in the synovial membranes that line your joints. In addition to pain, it can trigger significant deformation of your bone and cartilage, as well as causing joint deformity.
Many people with arthritic knees correlate changes in their pain levels with changes in the weather, the American Academy of Orthopaedic Surgeons reports. John Hopkins Medicine lists several potential theories for weather-related changes. According to one theory, drops in barometric pressure associated with rainy, cold weather allow inflamed tissue in your joints to expand further, leading to increased levels of pain. Additional potential explanations include lack of pain-reducing exercise in cold weather, drops in pain tolerance associated with cold weather, and mood alterations associated with rainy, cold weather.
Researchers have produced conflicting results when measuring weather's effects on pain, Johns Hopkins Medicine reports. On one hand, a study conducted in Argentina showed significant links between rheumatoid arthritis symptoms and high barometric pressure and humidity, as well as significant links between osteoarthritis symptoms and high humidity. On the other hand, a study of osteoarthritis patients conducted in Florida did not show any significant increases in weather-related knee pain. In a third study reported by the Arthritis Foundation, researchers at Tufts University noted in 2007 that either drops in temperature or increases in barometric pressure can worsen your arthritis symptoms.
Moving to a dry, warm climate may improve your joint pain, Johns Hopkins Medicine notes. However, making such a move will not guarantee you freedom from pain, and distancing yourself from social support systems may stress you significantly in other ways. If you live in a colder or wetter climate, ask your doctor for advice on ways to relieve weather-related pain in your knees or elsewhere in your body.