Arthritis is a general term that means inflammation in a joint. Joint inflammation is characterized by redness, warmth, swelling, and pain within the joint.
Rheumatoid arthritis is a type of chronic arthritis that typically occurs in joints on both sides of the body (such as hands, wrists, or knees). This symmetry helps distinguish rheumatoid arthritis from other types of arthritis. It is classified as an autoimmune disease in which the body attacks its own tissues. The primary cause appears to be delayed food allergies and related problems of abnormal permeability of the intestinal wall. This allows undigested food particles to pass through the intestinal walls, into the blood stream where it is deposited into joints and other tissues. The immune system then attacks the tissues with abnormal particles in them.
In addition to affecting the joints, rheumatoid arthritis may occasionally affect the skin, eyes, lungs, heart, blood, or nerves.