Cataplasia refers to degeneration, deterioration or wasting away of cells or tissues. Some synonyms for cataplasia may include atrophy, necrosis, apoptosis, degeneration, decay, degradation, dematerialization, breakdown, dissolution, disintegration, erosion and regression. These terms describe the same process of decay or decline of biological structures, but refer to different stages of the process or different types of degeneration. Atrophy, for example, usually refers to a gradual wasting away of muscles or organs due to disuse, aging or disease. Necrosis, on the other hand, is a more sudden and destructive form of degeneration that can be caused by injury, infection or ischemia.