What is bursitis? Bursitis is a common condition that causes swelling and pain around muscles and bones. Bursitis is the swelling of the bursa, a small, fluid-filled sac that acts as a cushion between a bone and other moving parts, such as muscles, tendons, or skin.
What is rheumatoid arthritis? Rheumatoid arthritis (RA) is a chronic (long-lasting) disease that mostly affects joints, such as the wrist, hands, feet, spine, knees, and jaw. In joints, RA causes inflammation that leads to: Pain. Swelling Stiffness. Loss of function. Rheumatoid arthritis is an autoimmune disorder because the immune system attacks the healthy joint tissues. Normally, the immune system helps protect the body from infection and disease. RA may cause you to feel unusually tired, to have occasional fevers, and to have a loss of appetite. It also may cause other medical problems in the heart, lungs, blood, nerves, eyes