One of the most common ways the immune system reacts to any type of bodily injury. Inflammation can occur in joints, on the skin, within organs, and so forth. It is characterized by redness, warmth, swelling and pain.
The body's inflammation response can be triggered by a number of causes, including an infection, a foreign body, decreased or compromised blood flow, extreme heat or cold, or radiation. In lupus and other autoimmune diseases, the reaction produced during inflammation and repair can be exaggerated and harmful to the body.