Demi Lovato revealed that she suffered three strokes and a heart attack following her 2018 drug overdose.

On Wednesday (Feb. 17), the “Anyone” singer released the trailer for her upcoming YouTube documentary, Demi Lovato: Dancing With the Devil.

The trailer reveals startling, never-before-shared details about Lovato's overdose incident. "I had three strokes," she shares in the promo clip, referring to her July 2018 drug overdose. "I had a heart attack. My doctors said that I had five to 10 more minutes."

At one point in the trailer, a photo of Lovato's hand with an IV attached to it flashes on the screen.

The trailer also features Lovato's family, friends and co-workers speaking about the pop star's life, struggles, near-death experience and sobriety.

"We're watching all of her blood come out of her body into a machine," her mother, Dianna De La Garza, says, while Lovato's friend Matthew Scott Montgomery reveals that at the time of her hospitalization, the singer couldn't even "see anything," suggesting that she was temporarily rendered blind.

Elton John and Christina Aguilera also appear in the trailer, speaking about the pitfalls of childhood and teenage fame, as well as Lovato's troubled journey.

At one point in the video, Lovato holds up her ring finger and shows off her engagement ring, before revealing a bare finger in another clip just a moment later, alluding to her broken engagement to Max Ehrich.

"I was left with brain damage and I still deal with the effects of that today," Lovato told Billboard after the trailer's premiere. "I don't drive a car because of blind spots in my vision ... I had a lot of trouble reading."

Demi Lovato: Dancing With the Devil debuts on YouTube March.

Celebrities Who Opened Up About Mental Health

More From Cars 108