Corruption is a condition which occurs when a magic user cast too many powerful spells in a short time or tries to cast a spell that requires more energy then he has. It starts with a magical overload. Magical energy is escaping from the body through the skin as beams of white light. It lasts for about 5 minutes. The overload causes the body to deform. In most cases, the deformation is limited only to rapid ageing, but there were cases of more extreme deformations. What all the cases have in common is an almost complete disappearance of higher brain functions. Their behaviour is based solely on instinct to find food. Affected are also very aggressive and attack everyone and everything.
Modern medicine found a cure for the Corruption. The cure must be given during the first 24 hours or it won't work. The good side of the cure is that it cures even the most severe deformations that occurred because of the Corruption. If an affected person is found after more than 24 hours he should be contained and killed in a most humane way possible.
Magic Academies and health centres organise safe magic courses in which they talk about the Corruption and teach how to know when you are reaching the overload. The number of Corruption cases has fallen 70% since the beginning of the prevention program in the 1950s.