Inflammation. In some diseases, like arthritis, the body's defense system - the immune system - triggers an inflammatory response when there are no foreign invaders to fight off. 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: Rheumatoid arthritis, Psoriatic arthritis, Gouty arthritis