Flux Blight, or simply the Blight, is a chronic disease that occurs in wizards and witches, although it can have notable and more severe effects in muggles. Flux Blight is a disease that one can catch if they are exposed to various Illusion spells at a long-term. Flux Blight can cause hallucinations, slight loss of mobility, insomnia, and, if left untreated, insanity and long-term memory loss. Hogwarts professor Donovar Crane is a known victim of the disease.