Autophagy is a catabolic process that helps cells to survive under stressful conditions such as starvation, viral infection, or accumulation of old proteins. During autophagy, autophagosomes and autolysosomes form to remove damaged organelles and degrade old proteins. Autophagy is also involved in cell death, and these types of cell death can be either autophagy-dependent or autophagy-mediated. Autophagy-dependent cell death is carried out by only components of the autophagic system. Excessive numbers of autophagosomes and autolysosomes are formed, and they degrade almost all cytoplasmic components and organelles in a non-selective manner. It also includes extreme mitophagy, where the majority of mitochondria are selectively removed by autophagy. Mitochondria removal creates an energy shortage which leads to cell death. In contrast, autophagy-mediated cell death occurs when autophagy triggers other cell death pathways such as apoptosis or necroptosis. For example, autophagy can degrade apoptosis inhibiting proteins leading to apoptosis.