Final answer:
Rheumatoid arthritis (RA) primarily affects the synovial joints and can lead to joint deformation, loss of movement, and severe disability. It is also associated with lung fibrosis, vasculitis, and coronary heart disease.
Step-by-step explanation:
Rheumatoid arthritis (RA) is an inflammatory disorder that primarily affects the synovial joints of the hands, feet, and cervical spine. It is an autoimmune disease where the body's immune system mistakenly attacks healthy tissue, causing joint inflammation, pain, and swelling. The disease can lead to long-term complications such as joint deformation, loss of movement, and severe disability. Additionally, RA is associated with lung fibrosis, vasculitis, coronary heart disease, and premature mortality.