Core Tip: For patients with arthritis, the presence of diseased tissue that cannot drain fluid from the cells in time with weather changes, resulting in higher cellular pressure in the diseased area than in the surrounding normal tissue, can cause a feeling of swelling and pain in the diseased area. For this reason, arthritis patients are usually able to predict the weather and the joints become a barometer of the weather. Why are there people with arthritis around us who can “predict” sudden changes in the weather? It starts with the intrinsic connection between weather changes and arthritis. ”Weather changes, such as cooling, chilling, cold, and increased wind speed, are visible and perceptible to the average person, and the body’s physiological mechanisms adjust to these changes accordingly. For example, when it is about to rain, the air pressure generally decreases and the humidity increases. In healthy people, the fluid in the cells leaks out on its own, leading to an increase in urine production as an adaptation to the weather. For arthritis patients, the presence of diseased tissues prevents them from draining fluid from their cells in time for weather changes, resulting in higher pressure in the cells of the diseased area than in the surrounding normal tissues, which can cause swelling and pain in the diseased area. This is one of the reasons why arthritis patients can anticipate weather changes. When the weather changes, there are movements and other changes in the positively and negatively charged atmospheric molecules in the atmosphere. As the different charges attract and hit 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. Normal people can always maintain a balance to this potential difference, while arthritis patients can release some inflammatory substances due to changes in local capillaries and tissues, making nerve endings compressed and producing soreness. Although changes in temperature, air pressure, humidity and many other elements can cause increased joint pain, none of these changes come as quickly as electromagnetic waves. So, often the weather is still sunny at the time, and the abnormal electromagnetic waves have already transmitted the information about the weather change, which 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 One study mentioned that when exploring the effects of weather changes on the pain sites of rheumatoid arthritis patients, it was found that the majority of patients’ pain occurred in the joint areas, with the greatest effect on the knee joint, which is determined by 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 was the lowest. When the subject was exposed to cold for 20 minutes and then measured the temperature of the different tissues, it was found that the temperature of the joints decreased the most. When the subjects returned to the pre-experimental temperature environment, the joint temperatures continued to drop, even lower than the lowest temperatures that occurred during the experiment, indicating that joint temperature recovery was also slow. The rheumatic disease patients have poorer thermoregulatory mechanisms than healthy people, so the joint area is most sensitive to weather changes. The knee joint is the main weight-bearing joint of the 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 movement 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. Healing in desert areas can provide relief Since arthritis is so closely related to weather changes, this has led to the idea of using weather conditions to target arthritis treatment. Experiments have shown that arthritis patients can achieve satisfactory results when they go to desert areas where the climate is dry, the sun shines for long periods of time, the temperature difference between day and night is large, and the changes in air pressure and humidity are small. However, when the patients returned to their original environment, some of them still had a relapse of their old 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 have an auxiliary effect on 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 a variety of interrelated factors and mutual constraints. An environment with less variation in air pressure and humidity may help improve joint pain due to weather changes in arthritis patients.