Autoimmunity and Allergies

Autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an "autoimmune disease". An autoimmune disease is a condition in which your immune system mistakenly attacks your body. Normally, the immune system can tell the difference between foreign cells and your own cells.

In an autoimmune disease, the immune system mistakes part of your body — like your joints or skin as foreign. It releases proteins called autoantibodies that attack healthy cells. Some autoimmune diseases target only one organ.

Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. Allergies exist in many different forms. Allergy symptoms occur when your immune system overreacts to an allergen—something that usually is harmless, such as plant pollen, dust mites, molds, insect stings or food.