Osteoarthritis is the most common form of arthritis. Still, the other two common types of arthritis include rheumatoid arthritis and psoriatic arthritis. Osteoarthritis is a joint condition that causes the cartilage to break down and the bones to rub together. This can cause pain, stiffness, swelling, and deformity. Rheumatoid arthritis is an inflammatory condition that causes painful, swollen joints and sometimes leads to joint deformity. Some people develop rheumatoid arthritis because their immune system attacks their bodies' own healthy tissue surrounding the joints. You are more likely to develop this type of arthritis if you have a family history of the condition or another autoimmune disorder, such as thyroid disease or type 1 diabetes. Psoriatic arthritis is a form of arthritis associated with psoriasis. Joints are often affected by psoriatic arthritis, but skin symptoms like red scaly patches or itchy skin can also occur as part of the condition.