A near-death experience (NDE) is an intensely vivid experience that occurs when a person is close to death or clinically dead, often during cardiac arrest, severe trauma, or deep anesthesia. These experiences share a remarkably consistent set of features: a sense of leaving the body, moving through a tunnel toward brilliant light, encountering deceased loved ones, and feeling overwhelming peace. Between 6% and 39% of cardiac arrest survivors report having one, and the experiences often reshape a person’s values, beliefs, and personality for the rest of their life.
What People Report During an NDE
Despite happening to people of different ages, cultures, and beliefs, NDEs follow a surprisingly recognizable pattern. The most commonly described features include a sensation of separating from the physical body, thinking with unusual speed and clarity, being drawn into a tunnel or darkness, and encountering a brilliant light. Many people describe a profound sense of peace, well-being, or unconditional love that exceeds anything they’ve felt before.
Some experiences go further. People report a “life review” where important events from their past play back rapidly, sometimes from the perspective of others involved. Some feel they have access to unlimited knowledge or receive previews of future events. Encounters with deceased relatives or figures interpreted as religious beings are common. Many describe reaching a border or point of no return, after which they feel pulled or choose to return to their body.
Not every NDE includes all of these elements. Researchers use a standardized 16-item questionnaire, developed by psychiatrist Bruce Greyson, to measure the depth and characteristics of the experience. It asks about altered time perception, heightened senses, feelings of cosmic unity, separation from the body, encounters with other beings, and the presence of a boundary. A score of 7 or higher out of 32 qualifies as a near-death experience for research purposes, with the average score around 15.
How Common Are NDEs?
A scoping review of prospective studies on cardiac arrest patients found that the reported incidence of NDEs ranged from 6.3% to over 39%, depending on the study. In-hospital cardiac arrests tended to produce a wider range of reported rates (from about 6% to 39%), while out-of-hospital arrests clustered more consistently around 18% to 21%. The variation likely reflects differences in how quickly patients were resuscitated, how soon they were interviewed afterward, and how the experience was defined in each study. At the upper end, more than one in three cardiac arrest survivors may have some form of NDE.
What Happens in the Brain
No single theory fully explains NDEs, but several biological mechanisms likely contribute to different features of the experience.
The out-of-body sensation appears connected to a brain region called the temporoparietal junction, which normally integrates sensory information to create your sense of being located inside your body. When researchers disrupted this area using magnetic stimulation in healthy volunteers, it impaired their ability to mentally picture their body’s position in space. In an epileptic patient whose seizures originated from this same region, the seizure focus partially activated during tasks that mimicked her out-of-body perceptions. This suggests that when the temporoparietal junction malfunctions, whether from oxygen loss, seizure activity, or other stress, the brain can lose its grip on where “you” are relative to your body.
Carbon dioxide buildup in the blood may play a role in the emotional and mystical qualities of NDEs. Higher carbon dioxide levels appear to have an excitatory effect on the brain’s emotional centers, which could trigger the intense feelings of peace, unity, or awe that people describe. However, blood carbon dioxide levels don’t always reflect what’s happening in the brain itself, making the relationship harder to pin down. One complicating factor: higher carbon dioxide also indicates better blood flow during cardiac arrest, which would make patients more likely to remember whatever they experienced, not necessarily more likely to have the experience in the first place.
One of the more intriguing theories involves DMT, a powerful psychoactive compound the body produces naturally in small amounts. Stress, oxygen deprivation, and tissue changes can all influence its production. Early research found only trace levels in mammalian brains, but more recent studies in rodents have identified DMT at levels comparable to established neurotransmitters and discovered previously unknown production pathways. DMT has also been linked to protection against oxygen deprivation and oxidative stress, raising the possibility that its release during a life-threatening crisis could serve a protective function while simultaneously generating vivid perceptual experiences. This remains speculative in humans.
Evidence of Awareness During Cardiac Arrest
The AWARE II study, a multi-center investigation led by Sam Parnia, provided some of the most rigorous clinical data on consciousness during cardiac arrest. Of 567 in-hospital cardiac arrests, 53 patients survived, 28 completed interviews, and 11 of those (39.3%) reported memories or perceptions suggestive of consciousness during the event. The experiences fell into four categories: awareness emerging during CPR itself, awareness in the period immediately after resuscitation, dream-like experiences, and what the researchers termed “recalled experiences of death,” which correspond to classic NDE features like transcendence and encounters with other beings.
Perhaps the study’s most striking finding was physiological. Despite severe oxygen deprivation to the brain (measured at levels well below normal), normal electrical brain activity consistent with conscious processing appeared as long as 35 to 60 minutes into CPR. This challenges the assumption that the brain shuts down within seconds of cardiac arrest and suggests a potential biological marker for when these experiences occur. The study did attempt to test whether patients could perceive specific visual images placed in the room during resuscitation, but no one identified them. One patient did identify an auditory stimulus.
Children’s NDEs
Children report the same core elements as adults: the tunnel, the light, encounters with other beings, feelings of peace. This consistency is notable because young children have less cultural exposure to religious imagery or media depictions of dying, which weakens the argument that NDEs are simply the brain projecting learned expectations. One difference researchers have identified is that children don’t report depersonalization, the feeling of watching yourself as if you’re someone else, which occasionally appears in adult accounts.
How NDEs Change People
The aftereffects of a near-death experience are often more dramatic than the experience itself. People consistently report a greater sense of purpose, deeper compassion for others, increased self-esteem, a stronger focus on spirituality, and a marked decrease in interest in material wealth or social status. Many describe a desire to serve others that wasn’t present before.
The most well-documented change is a reduction in the fear of death. In one study, 80% of people who had NDEs reported decreased fear of death, compared to 29% of people who came close to death without an NDE. Another study of cardiac arrest patients found 82% of those with NDEs reported less fear of death, versus just 2% of those who didn’t have the experience. In one Australian study of 50 people, every single participant reported no fear of death after their NDE, compared to only 20% of the same group before. The intensity of the NDE matters too: people who experienced a life review, encountered a mystical being, or felt profound joy during the event tended to show the greatest reductions in death anxiety.
These changes tend to be permanent. Researchers have found that the intensity of the NDE correlates strongly with the degree of spiritual transformation afterward. People frequently describe a fundamental shift in their worldview, one that persists years and even decades later.