Lack of oxygen to the brain: Cerebral anoxia often causes sensory distortions and hallucinations and sometimes cerebral anoxia is used to explain features of the near-death experience.

A near-death experience (NDE) consists of experiences of people after they have been pronounced clinically dead, or who have been very close to death.

Typical features of the near-death experiences are an OBE (Out of Body Experience), a fully conscious experience in which the person's center of awareness appears to be outside the physical body, a life review, a tunnel experience, a light, coming to a boundary (marking death), seeing dead friends, and relatives, experiencing a loving or divine presence, and making a choice (or being told) to return.

Occasionally near-death experiences can be frightening and distressing, and often have profound effects on the person's later life.