Near-Death Experiences Evidence for Their Reality - PMC - NIH
: Hypoxia typically causes confusion and agitation, whereas NDEs are characterized by clarity and peace. Evidence of the Afterlife - The Science of Near...
: While endorphins can reduce pain, they linger in the system for minutes; NDE sensations of bliss typically end instantly when a patient is resuscitated. Near-Death Experiences Evidence for Their Reality - PMC
Science often looks for physical causes, but many common theories struggle to explain the full NDE phenomenon: Evidence of the Afterlife - The Science of Near...
: Experiencers often meet people they knew who had died.
: Experiences like those from ketamine are often described as unpleasant or chaotic, unlike the organized narrative of an NDE. Notable Research & Books
Only of these encounters involve living persons, and some involve meeting relatives the experiencer didn't even know were dead.