
Near-death experiences are tricks of the mind triggered by an overload of carbon dioxide in the bloodstream, a new study suggests.
Many people who have recovered from life-threatening injuries have said they experienced their lives flashing before their eyes, saw bright lights, left their bodies, or encountered angels or dead loved ones.
In the new study, researchers investigated whether different levels of oxygen and carbon dioxide—the main blood gases—play a role in the mysterious phenomenon.
The team studied 52 heart attack patients who had been admitted to three major hospitals and were eventually resuscitated. Eleven of the patients reported near-death experiences.
During cardiac arrest and resuscitation, blood gases such as CO2 rise or fall because of the lack of circulation and breathing.
“We found that in those patients who experienced the phenomenon, blood carbon-dioxide levels were significantly higher than in those who did not,” said team member Zalika Klemenc-Ketis, of the University of Maribor in Slovenia.