Cells within a living organism can die in one of two ways. The first type of cell death, necrosis, occurs when cells and tissues are damaged by mechanical means or toxins, or are starved of oxygen or nutrients. Necrotic cells often swell up and burst, releasing their contents into the extracellular environment and possibly causing inflammation (see Key Concept 42.1). Apoptosis, or programmed cell death, is a genetically determined series of events that occurs during normal developmental processes and in adult tissues as well.