Arthritis is inflammation of one or more joints. A joint is the area where 2 bones meet. There are more than 100 different types of arthritis.
Joint inflammation; Joint degeneration
Arthritis involves the breakdown of cartilage. Normal cartilage protects a joint and allows it to move smoothly. Cartilage also absorbs shock when pressure is placed on the joint, such as when you walk. Without the normal amount of cartilage, the bones rub together. This causes swelling (inflammation), and stiffness.
Joint inflammation and damage may result from:
- An autoimmune disease (the body's immune system mistakenly attacks healthy tissue)
- Broken bone
- General "wear and tear" on joints
- Infection, most often by bacteria or virus
- Crystals such as uric acid or calcium pyrophosphate dihydrate
In most cases, the joint inflammation goes away after the cause goes away or is treated. Sometimes, it does not. When this happens, you have long-term (chronic) arthritis.
Arthritis may occur in men or women. Osteoarthritis is the most common type.
Other, more common types of inflammatory arthritis include: