In recent years, the onset of arthritis has gradually become younger, and some younger patients can also develop rheumatoid arthritis manifestations. The common causes of rheumatoid arthritis are as follows: 1. environmental factors: smoking can lead to specific antibody CCP positivity; 2. genetic factors: the incidence of rheumatoid arthritis in first-degree relatives can be about 11%; identical twins, one of whom has rheumatoid arthritis, have a 12%-30% chance of developing the other; 3. immune dysregulation factors: including T-lymphocyte and B-lymphocyte dysfunction; 4. The rheumatoid arthritis attack can be triggered by exposure to cold water and humid environment.