Hypersensitivity Reaction

A hypersensitivity reaction occurs when the immune system overreacts to a harmless substance, like pollen, certain foods, or medications. There are four main types: immediate allergic reactions (like hay fever or anaphylaxis), cytotoxic reactions (where antibodies attack the body’s own cells), immune complex reactions (where antibody-antigen complexes trigger inflammation), and delayed reactions (like contact dermatitis). These reactions can lead to symptoms ranging from mild irritation to severe health issues. Essentially, it's the body mistakenly treating a non-threat as a danger, resulting in sometimes harmful responses.