When the joint become damaged, the body’s response is inflammation. There are five signs of inflammation in the body: redness, swelling, heat, pain, and eventually reduced range of motion.
Each disease causes the inflammation in different ways:
- Gout and pseudogout: The deposit of crystals into the joint causes both of these diseases. The body responds to these crystals by releasing chemicals that cause inflammation. In gout the crystals are made of uric acid; in pseudogout they are made of calcium pyrophosphate.
- Infectious arthritis: The body attacking microorganisms that have moved into the joint is what causes inflammation in infectious arthritis.
- Osteoarthritis (Degenerative Joint Disease): Inflammation is a later sign in osteoarthritis and occurs when the joint itself begins to deteriorate.
- Rheumatoid arthritis (autoimmune): Inflammation is a common early sign of rheumatoid arthritis, as the body mistakes the joints for something foreign and attacks them.