Patients with rheumatism have traditionally been told that “bad weather makes you more uncomfortable” and that “increased pain means the weather is going to get worse. Recently, a research group from the Kyoto University Hospital Rheumatology Center analyzed the diagnostic data of about 20,000 patients and the weather information published by the Meteorological Agency, and for the first time statistically and practically confirmed the correlation between air pressure and rheumatism. Symptoms of rheumatism (Rheumatism), such as joint pain and swelling, are exacerbated by lower air pressure due to rain or cloudy weather. Rheumatism causes inflammation in the body’s joints, making them swollen and painful. The majority of rheumatism patients are women, and the number of patients in Japan is estimated to be 700,000. If symptoms worsen, the joints become deformed and unable to function, causing a serious impact on life. In this study, scientists investigated data on about 20,000 patients who visited the hospital from 2005 to 2012, 80% of whom were women with an average age of 60 years, and analyzed the number of joints with pain and swelling at the time of diagnosis and the relationship between air pressure and temperature in Kyoto on that day. It was found that the lower the air pressure due to rain or cloudy weather, etc., the more patients complained of increased pain and swelling, and the number of joints with pain and swelling counted by doctors increased, and that the weather had the greatest impact three days earlier. In addition, there was a small relationship between rheumatism symptoms and humidity, but no correlation was found between it and air temperature. On the other hand, there was no correlation between blood data showing the degree of inflammation and weather, so the team concluded that weather does not influence the development of rheumatic disease. The team noted that although the mechanism by which the relationship between air pressure and rheumatic disease symptoms exists is not clear, it is statistically confirmed that the patients’ experience is indeed true.