When you think of arthritis, you think of inflammation. Inflammation is a process in which the body's white blood cells and immune proteins help protect us from infection and foreign substances such as bacteria and viruses.
In some diseases, however, the body's defense system (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 joints. Some types of arthritis associated with inflammation include:
The most common form of arthritis called osteoarthritis (also known as degenerative arthritis) is a bit of a misnomer. It is not believed that inflammation plays a major role in osteoarthritis. Other painful conditions of the joints and musculoskeletal system that are not associated with inflammation include fibromyalgia, muscular low back pain, and muscular neck pain.
What Are the Symptoms of Inflammation?
The symptoms of inflammation include:
Loss of joint function
Often, only a few of these symptoms are present.
Inflammation may also be associated with general "flu"-like symptoms including:
Fatigue/loss of energy
Loss of appetite
What Causes the Symptoms of Inflammation?
When inflammation occurs, chemicals from the body are released into the blood or affected tissues. This release of chemicals increases the blood flow to the area of injury or infection and may result in redness and warmth. Some of the chemicals cause a leak of fluid into the tissues, resulting in swelling. This process may stimulate nerves and cause pain.
What Are the Results of Joint Inflammation?
Increased blood flow and release of these chemicals attract white blood cells to the sites of inflammation. The increased number of cells and inflammatory substances within the joint can cause irritation, wearing down of cartilage (cushions at the end of bones), and swelling of the joint lining (synovium).
How Are Inflammatory Diseases Diagnosed?
Diagnosis of inflammatory joint diseases consists of all or some of the following:
Complete medical history and physical exam with attention to the pattern of joint involvement
Evaluation of other symptoms besides joint symptoms
Results of X-rays, blood tests, and other studies
Can Inflammation Affect Internal Organs?
Yes. Inflammation can affect organs as part of an autoimmune disorder. The type of symptoms depends on which organs are affected. For example:
Inflammation of the heart (myocarditis) may cause vague chest pain or fluid retention.
Inflammation of the small tubes that transport air to the lungs (bronchiolitis) may cause shortness of breath.