The guy says he had a heart attack and went to hell in 2016. That's what he saw!

The guy says he had a heart attack and went to hell.

The priest says he briefly went to hell in 2016.

He saw men walk like dogs and heard demons sing Rihanna's songs.

While many of the most publicized near-death experiences are more positive than this trip to hell, negative outcomes also happen.

In 2016, a Michigan priest named Gerald Johnson suffered a heart attack. He says he had a near-death experience (NDE) that took him to places he never thought he would go

Johnson recently took to TikTok to share the details of his traumatic NDE - far from the warm, luminous epiphany you might expect to hear from someone who is temporarily traveling to the great beyond.

“I wouldn’t wish this on my worst enemy,” Johnson says in a viral video. “I don't care what he did to me. Nobody deserves it.”

Johnson says that immediately after his heart attack in February 2016, his spirit left his physical body and descended into hell, entering through “the very center of the earth.” Although he says, “What I saw there is indescribable,” he did his best.

Johnson claims he saw a man who walked on all fours like a dog and was burned from head to toe.

Johnson also heard music in Hell, including Rihanna's "Umbrella" and Bobby McFerrin's "Don't Worry, Be Happy" - traditionally upbeat tunes. Only this time, the demons sang songs to "torment" people.

Johnson says his hellish NDE made him realize that he needs to forgive the people who wronged him instead of hoping for their punishment.

Perhaps Johnson's story sounds far-fetched to you. But scientists say that while many of the most publicized outcomes have positive effects, negative outcomes certainly do occur. Experts are just not entirely sure how or why.

Researchers, especially those from the International Association for Near Death Research, believe that NDEs are most likely due to changes in blood flow to the brain during sudden life-threatening events such as a heart attack, blunt trauma, or even shock. As your brain begins to lose blood and oxygen, electrical activity in the brain begins to decline. “Like a city losing power one area at a time, local areas of the brain go off one by one,” one expert told Scientific American.

During NDE, your mind continues to function, but without its normal operating parameters. Whether it's just a lack of oxygen, some kind of anesthesia, or the neurochemical response to trauma as it was supposed to be, NDE leaves those who experience it with real, sometimes traumatic memories. We may not know how this memory happened - and, unlike Johnson and his trip to Hell, the victims may not want to ever talk about it again - but it could be life-changing.