Autoantibody is a type of antibody (See: Antibodies) that are produced by the immune system. As against the regular antibodies, autoantibodies, mistakenly attack the target the body’s own cells, and tissues as intruders and destroy them. They lack the mechanisms to distinguish between foreign entities and the body’s own cells. In normal circumstances, the immune system of the body has the ability to distinguish between foreign entities and own cells. The immune system is designed to fight against bacteria, virus, and other chemicals. However, in the case of autoantibodies, due to a state called autoimmunity where the immune system targets the healthy tissues of the body, it leads to autoimmune disorders. Autoantibodies are produced in the B cells either randomly or as a response to a foreign protein entering the body. This leads to diseases like type 1 diabetes, Graves’ disease, Hashimoto’s thyroiditis, Addison’s disease, and celiac disease.