Many studies have shown that there is a relationship between the development of rheumatoid arthritis (RA) and infection by certain viruses. Why do viral infections cause rheumatoid arthritis? This is because when the virus invades the body, the body’s immune cells produce an abnormal antibody, which is medically called a “home antibody”. The “home antibodies” are often indistinguishable from the enemy, mistakenly treating normal tissues and organs as germs to fight, destroying normal joint tissues and resulting in the onset of rheumatoid arthritis. There is no conclusive evidence as to which virus causes rheumatoid arthritis. Rheumatoid arthritis has a relationship with genetic factors, mainly in the form of a higher incidence of the disease in certain families, and a higher incidence of rheumatoid arthritis in families with people who have rheumatoid arthritis. Rheumatoid arthritis is often found in several members of the same family, and the incidence of rheumatoid arthritis in children whose parents have suffered from rheumatoid arthritis is much higher than that in children whose parents do not have rheumatoid arthritis. In addition, monozygotic twins have a 27% chance of developing rheumatoid arthritis at the same time, while dizygotic twins have a 13% chance, which is much higher than the general population. According to statistical analysis, the blood type of rheumatoid arthritis patients is more in AB and A type. According to the gender statistics of rheumatoid arthritis patients, the ratio of men to women in rheumatoid arthritis patients is 1:3, with women significantly more than men. This is because the onset of rheumatoid arthritis is closely related to the level of estrogen in women, and the higher the level of estrogen, the more the onset of rheumatoid arthritis, which is one of the reasons why young women are prone to rheumatoid arthritis. Cold, dampness, fatigue, malnutrition, trauma, smoking, mental factors, etc., are the triggering factors for the recurrence of rheumatoid arthritis, but the majority of people who fall ill often can not find obvious triggers. 90% of rheumatoid arthritis patients are very sensitive to climate change, and thus have the name of “weather joints”. The disease develops, worsens or deteriorates around the spring equinox and fall equinox, or in February or August. Various kinds of infections can also induce or aggravate rheumatoid arthritis, and joint sprains, bruises and bone fractures are also triggers for the development of rheumatoid arthritis. Psychological trauma, especially in children, has a higher incidence after parental separation or death. The incidence is also higher in people with low socio-economic status and lower education. Medical studies also show that 42% of rheumatoid arthritis patients are smokers, while 22% of non-rheumatoid arthritis patients are smokers. This indicates that rheumatoid arthritis is related to the amount of smoking, and the greater the amount of smoking, the higher the risk of developing the disease, indicating that heavy smoking has a close relationship with rheumatoid arthritis.