Definition of hypersensitivity

The term "hypersensitivity" was coined in the early 20th century to describe an abnormal sensitivity to external stimuli, such as allergens, irritants, or even normal substances. The word is derived from the Greek words "hyper" meaning "above" or "beyond" and "sensitiveness" meaning "sensitivity". The concept of hypersensitivity was first recognized by German physician Clemens von Pirquet in 1905, who described it as a condition where an individual's immune system overreacts to a specific substance, leading to exaggerated symptoms. The term was initially used to describe allergic reactions, but it has since been expanded to include other conditions, such as hypersensitivity to light, sound, or emotions. The term "hypersensitivity" is now widely used in medicine to describe a range of conditions where an individual's body responds excessively to a stimulus, leading to abnormalities in their physiological or psychological functioning.