Lycanthropy is the disease or magical curse associated with turning a being into a lycanthrope. Although the term specifically refers to the cause of werewolves, it has been expanded by some to refer to all were-creatures.
The exact treatment of lycanthropy varies from legend to legend and universe to universe. Some treat it as a completely magical curse, spread through bites and scratches from lycanthropes or imposed as a terrible punishment by powerful forces. Others treat it as a disease, sometimes natural, sometimes artifically created, and sometimes magical in nature. Still other universes treat lycanthropy as a condition which is genetically inherited. Many universes combine these approaches.