Arthritis: What is it and how can you identify it? Arthritis occurs when the joints in the affected area become inflamed. Inflammation is when the body reacts to a disease, injury or other problem in the affected area. Inflammation can be described as swelling, stiffness and redness in the affected area. It can also cause tenderness and warmth. Inflammation can cause tissue damage. Who is Arthritis Most Affective? There are many types of arthritis. This means that there is a…