Necrosis is the death of a group of cells or tissue that leads to a state of rot. Unlike apoptosis, in which the organism causes the death of diseased cells, necrosis is due to various causes such as lack of blood supply (ischemia), toxic substances, trauma, various pathogen infections, ionizing radiation autoimmune diseases, entre otros. among others. The necrosis is irreversible. The diabetic foot is an example of necrosis.