Autoimmune disease is a group of disease that happens due to immunity. Antibody, is the major parts of immune system that fight against the foreign particles in body to destroy them, either these can not create any harmful effect. Antibody, detects the foreign particles and attack these to destroy. Some times these antibody, may do wrong. Antibody may count the essential organ of the body as foreign particles. Such as in most case antibody count hard and rigid bone as foreign particles. With the role of antibody, they attacks on these to destroy. In that case, if any organ of the body genetically less stronger, these organ of the body may be affected by antibody or necessary microorganism of the body. Osteoarthritis is a most common autoimmune disease. Bone pain is also a kind of autoimmune disease. Osteoarthritis is a disease, specially most common in women. Women are more familiar with autoimmune disease.