Since rheumatoid arthritis (RA) and osteoarthritis (OA) are both arthritis, it is easy to understand why patients tend to associate them together. “Arthritis” is an umbrella term that encompasses more than 100 rheumatic/rheumatoid diseases. As listed below, there is a clear distinction between RA and OA. Characteristics of rheumatoid arthritis First, rheumatoid arthritis is a type of autoimmune disease. This type of disease occurs when the body’s immune system, which is supposed to protect the body, turns to attack our own healthy tissues. Rheumatoid arthritis is a chronic inflammatory joint disease that usually involves the small joints of the hands and feet. In the spine, the most susceptible areas are the cervical region and the small joints. The joints of the body are surrounded by a membranous layer of tissue called synovium. When you have rheumatoid arthritis, the white blood cells in the blood (which normally protect the body) attack the synovial tissue, creating inflammation and leading to joint pain and reduced mobility. Eventually, the synovial membrane thickens and forms a harmful “covering” over the joint, causing the joint to lose its normal physiological function. Although the exact cause of RA is not known, we do know that it may be related to rheumatoid factor antibodies (or proteins produced by the body’s immune system), which can be detected through blood tests. Everyone has a certain level of rheumatoid factor in their body, but if it exceeds the standard by too much, the immune system will be affected. However, the presence of rheumatoid factor does not necessarily mean that you have RA; it is not the best way to detect RA. Characteristics of Osteoarthritis Osteoarthritis is more common and generally less symptomatic than rheumatoid arthritis, and while RA usually affects the cervical spine, OA can accumulate throughout the spine: cervical, thoracic, and lumbar. Unlike RA, OA is not strictly speaking considered a disease. It is a natural process caused by aging, and you may have heard it also referred to as “degenerative joint disease” or “spinal degeneration. OA is essentially caused by aging, for example, when an older patient develops painful swollen joints that lead to spinal cord compression, we call it “osteoarthritis. But some people develop osteoarthritis earlier than others, and that is natural because we all age to varying degrees. Osteoarthritis can be caused by a number of specific, age-related factors, including disc degeneration and cervical/lumbar spinal stenosis. The main feature of osteoarthritis is damage to the cartilage, which is the cushioning device within the joint. When the cartilage in the body begins to wear away, the protective cushion between the bones in the joint is affected and the bones rub against each other thus causing severe pain. The main difference between RA and OA is that rheumatoid arthritis is an inflammation of the tissues surrounding the joints, while osteoarthritis is a lesion of the cartilage between the joints. Of course there are other differences between the two, for example, they both have their own different symptoms and management. But rheumatoid arthritis and osteoarthritis have one significant similarity: they can both affect our spine.