Throughout human history, there have been numerous reports of a baffling process when individuals have come to the brink of death. This process, referred to as near death experiences (NDEs), cause an individual to experience events that even the most advanced science can still not answer. This review serves as a reference for the factors, phenomenology, and measurement techniques for near death experiences as well as summarizing these experiences in certain conditions, such as cardiac arrest and admission of anesthetics. Discussed are the theories, effects, analyses of specific processes involved pertaining to experiences of those who walked along the edge of death.