How is the wrist and ankle cold and painful, and the knee hurts?

Arthritis patients often feel more severe joint pain before rain or snowstorm comes; When seasonal changes such as vernal equinox and autumnal equinox approach, symptoms of rheumatism will also appear. Over time, some experienced patients can predict the weather changes, and the accuracy is sometimes as good as the weather forecast. So, what does arthritis have to do with the weather? It will aggravate the symptoms: someone has done an experiment: a "climate control room" has been specially built, which can control and automatically record five climate indicators (temperature, humidity, air pressure, airflow and ionization) at will. Then arthritis patients who knew nothing about the experiment were put into the "climate control room", and the researchers observed them scientifically. The results show that when the humidity increases and the air pressure decreases, the symptoms of these patients get worse, but the continuous high humidity and low air pressure do not make the symptoms worse. This result is consistent with the phenomenon that many patients feel worse symptoms before the weather changes such as rain and snowstorm. Among arthritis patients, 80%- 9 0% have this phenomenon, and 10%- 20% are not affected by weather changes. Some people may wonder why arthritis patients can "predict weather changes" and why they are so sensitive to weather changes. Studies have shown that when the humidity increases and the air pressure decreases, the liquid in normal human cells oozes and the urine volume increases to adapt to the external weather changes. However, in patients with arthritis, the joint lesion tissue can't discharge fluid with the weather change, which makes the intracellular pressure in the inflamed area higher than that in the surrounding normal tissue, leading to aggravated pain and local swelling. This is not an inducement: arthritis is closely related to the weather, but this does not mean that weather changes are the cause of arthritis. Arthritis patients are all over the world. It used to be thought that the onset of arthritis was related to the cold and warm climate. The incidence of arthritis in tropical areas is very low, and cold may cause arthritis attacks. However, subsequent surveys show that the incidence of arthritis in Ecuador and Puerto Rico near the equator is almost the same as that in Hiroshima and Nagasaki in Japan. Finland, located between the Arctic Circle, has a lower incidence rate than the Netherlands. So far, it has not been proved that the weather can cause any kind of arthritis, and geographical latitude has nothing to do with the onset of arthritis.