Bone spurs (also called osteophytes) are smooth, hard bumps of extra bone that form on the ends of bones. They often pop up in the joints — the places where two bones meet. Most bone spurs don’t cause problems. But if they rub against other bones or press on nerves, you might experience pain and stiffness. The most common cause of bone spurs is joint damage from osteoarthritis or degenerative joint disease. The cushioning between your joints and the bones of your spine can wear down with age. Bone spurs also often form after an injury to a joint or tendon. When your body thinks your bone is damaged, it tries to fix it by adding bone to the injured area.