Rheumatoid arthritis is a relatively common autoimmune disease that primarily affects the joints. The etiology of the disease is unclear, but there are many known risk factors. Citrullinated proteins and the immune system's response with the production of ACPAs (anti-citrullinated protein antibodies) are associated with the preclinical phase of the disease. The symptoms of the disease are relatively similar among patients, but the mechanisms of disease progression are uneven. This is also the case with synovial inflammation, where patients show differences in which cytokines and immune cells are present in the joint tissue. In people with rheumatoid arthritis, various immune cells infiltrate the joint tissue, where they secrete different cytokines that cause inflammation, leading to tissue damage. The inflammation also affects the rest of the body, increasing the risk of developing other diseases. Most patients never achieve remission, although this is the main goal of treatment. Therefore, new treatment approaches continue to be actively researched, such as blocking signaling pathways of transcription factors associated with rheumatoid arthritis, stem cell therapy, and chronotherapy.