Inflammation is a process by which the body's white blood cells and chemicals protect our bodies from infection by foreign substances, such as bacteria and viruses.
In some diseases, however, the body's defense system - the immune system - triggers an inflammatory response when there are no foreign substances to fight off. In these diseases, called autoimmune diseases, the body's normally protective immune system causes damage to its own tissues. The body responds as if normal tissues are infected or somehow abnormal.
Some, but not all, types of arthritis are the result of misdirected inflammation. Arthritis is a general term that describes inflammation in the joints. Some types of arthritis associated with inflammation include the following:
Other painful conditions of the joints and musculoskeletal system that may not be associated with inflammation include osteoarthritis, fibromyalgia, muscular low back pain and muscular neck pain.