In general, arthritis occurs when your joints swell or feel tender. Osteoarthritis, where the cartilage protecting your bones breaks down, and rheumatoid arthritis, an autoimmune disease where your immune system attacks your joints, are the most common types of arthritis. Other common types of arthritis include:
Psoriatic arthritis Traumatic arthritis Lupus Ankylosing spondylitis Gout Juvenile arthritis Lupus Less common types of arthritis include septic arthritis, which comes from a penetrating injury that spreads germs through your bloodstream, or reactive arthritis, which occurs when an infection in another part of your body causes joint pain.