A study suggests that people who report having "near-death experiences," such as seeing lights or divine encounters, have increased levels of carbon dioxide in the blood, Agence France-Presse reported.
According to research, between 11 and 23 percent of heart attack survivors report having near-death experiences.
The study, which is reported in the journal "Critical Care," looked at 52 heart attack victims. Eleven had a near-death experience and the common link was a high level of carbon dioxide in the blood.
Researchers said more work still needs to be done to confirm the findings, but understanding a near-death experience is important.