The pain seems to be radiating from your joints, with an aching feeling that prevents the easiest daily activities. It must be arthritis, right? Surprisingly, sometimes it isnt. Arthritis is a disease of the joint tissue, which causes the joints breakdown and degeneration. Yet, there are many conditions that can make your joints feel as if they are arthritic while, in fact, something else may be causing the pain, says Matthew Bunyard, MD, a rheumatologist in the Department of Rheumatic and Immunologic Disease at Cleveland Clinic. "If it is arthritis, wed see swelling in the joint, tenderness, and pain when the joint is moved, or a loss of motion in that joint. These symptoms allow us to see that theres truly something wrong with the joint itself."