Before the “change of weather” lesions will be painful Weather changes, such as cooling, cold, cold, increased wind speed, etc., is generally seen and perceived by people, the body’s physiological mechanisms will also make corresponding adjustments to such changes. For example, when it is about to rain, the air pressure generally decreases and the humidity increases, and healthy people can adapt to the weather by leaking fluid out of their cells and increasing the amount of urine. For arthritis patients, because of the presence of diseased tissues, the fluid in the cells cannot be drained in time with the weather changes, resulting in higher pressure in the cells of the diseased area than in the surrounding normal tissues, which causes a feeling of swelling and pain in the diseased area. This is one of the reasons why arthritis patients can anticipate weather changes. When the weather changes, the positively and negatively charged atmospheric molecules move and other changes occur. As the different charges attract each other, a series of electromagnetic phenomena and electromagnetic waves are generated, which can make the potential difference between positive and negative charges inside and outside the cells of the human body. In normal people, this potential difference is always balanced, but in arthritis patients, due to changes in local capillaries and tissues, some inflammatory substances are released, which cause nerve endings to be compressed and produce soreness. Although changes in temperature, air pressure, humidity and many other factors can cause increased joint pain, these changes are not as fast as electromagnetic waves. This is why arthritis patients often start to experience pain before the weather changes, and is another important reason why they can anticipate weather changes. The knee joint is the most affected. Some studies have mentioned that the majority of patients with rheumatoid arthritis have pain in the joints, and the knee joint is the most affected, due to some characteristics of the joint itself. Experiments have been done to measure the temperature of different tissues in the body at room temperature, and the temperature of the joints is the lowest. When the subjects were exposed to cold for 20 minutes and then measured the temperature of the different tissues, the temperature of the joints decreased the most. When the subjects returned to the pre-experimental temperature environment, the joint temperature continued to drop, even lower than the lowest temperature that occurred during the experiment, indicating that joint temperature recovery was also slow. The rheumatism patients have poorer thermoregulation mechanisms than healthy people, so the joints are most sensitive to weather changes. The knee joint is the main weight-bearing joint in the human body, and synovial fluid is the liquid lubricant between joints, and its viscosity has a great influence on the sliding of the joint. The human knee joint contains about 0.5 ml of synovial fluid, and the viscosity of synovial fluid is directly related to the content of mucin. When the temperature drops, the mucin content in the synovial fluid increases, which increases the viscosity of the synovial fluid and affects the activities of the joint. In addition, the high plasma protein content also affects the protein in synovial fluid. Cold stimulation during sudden cooling can increase adrenaline secretion, and adrenaline can increase blood viscosity, all of which can increase the viscosity of synovial fluid, thus increasing joint resistance and causing joint pain. Since arthritis is so closely related to weather changes, it makes people think of using weather conditions to target arthritis treatment. Some people have found through experiments that arthritis patients can achieve quite satisfactory results when they go to desert areas where the climate is dry, the sun shines for a long time, the temperature difference between day and night is large, and the change in air pressure and humidity is small. However, when patients return to their original environment, some of them will still have a relapse of the disease. On the one hand, this shows that the treatment of joint diseases by climate factors alone cannot cure every patient; on the other hand, it also shows that the artificial creation of a suitable microclimate (normal air pressure and temperature, low humidity) can be useful for the treatment of arthritis. In conclusion, the influence of meteorological factors on arthritis is very complex, and is the result of the combined effect of multiple factors that are interrelated and mutually constrained. An environment with less variation in air pressure and humidity may help improve joint pain due to weather changes in arthritis patients.