Arthritis means "joint inflammation." It has various forms and may also have different symptoms. Osteoarthritis is mainly caused due to inflammation when the soft covering on the bones are damaged. They mostly occur on bones that bear the body weight. In other types of arthritis, like the rheumatoid arthritis, the narrow lining in the joint is affected. The joint-lining may become inflated and gradually the disease conquers the entire body and the patient fails to move. Arthritis may cause a total disability in many people. Arthritis mainly occurs in adults, but in some special cases even children may become a victim of this disease. Over a long period of time, the inflation may cause irreparable damage to the body, which can limit the daily chores of a person. Though the exact cause of arthritis is still not known, but it is a form of autoimmune disorder. The usual and normal defence system of the body gradually starts attacking the joints. At times, arthritis is hereditary. The ailment may also cause nodules that form in the knuckles, elbows, lower leg joint and elbows. It may also affect the lungs, eyes, nerves, or even the blood vessels.