Hypersensitivity

Hypersensitivity can be potentially harmful to the body and even can lead to death if not treated. It occurs when the normally protective immune system of the body responds abnormally. Many autoimmune diseases and allergies are categorized under the heading of hypersensitivity. Hypersensitivity is generally categorized into four types. Firstly is Type 1 hypersensitivity which is known as immediate hypersensitivity. The example of a disease caused by it is an allergic disease. The second type is Type 2 hypersensitivity also known as antibody-mediated hypersensitivity and examples of the disease are blood transfusion reaction or transplant rejection. Next is Type 3 hypersensitivity which is known as immune complex-mediated hypersensitivity and some of the autoimmune diseases are systemic lupus erythematous. The last type is Type 4 hypersensitivity also known as delayed-type and the example of autoimmune disease is Type 1 diabetes and Hashimoto Disease.