Demi Lovato says she couldn't go an hour without using cocaine before she went to rehab.

The 'Heart Attack' singer, who sought treatment for "physical and emotional issues" in October 2010, has admitted she used to "smuggle" the drug through airports and use it while flying first class before she hit rock bottom.

In an emotional interview with 'Access Hollywood Live' on Tuesday, the 21-year-old star said: "I've really never talked about this stuff before... I don't know if I should be sharing this.

"[W]ith my drug use I could hide it to where I would sneak drugs. I couldn't go 30 minutes to an hour without cocaine and I would bring it on airplanes. I would smuggle it basically and just wait until everyone in first class would go to sleep and I would do it right there. I'd sneak to the bathroom and I'd do it. That's how difficult it got and that was even with somebody [with me], I had a sober companion, somebody who was watching me 24/7 and living with me [and] I was able to hide it from them as well."

The 'X Factor' USA judge also confessed she would hide vodka in Sprite bottles and developed an eating disorder when she was just eight, but decided to finally seek help when she realized she could die.

Demi, who was interviewed alongside her mother, Dianna, who also battled an eating disorder, said: "It got really difficult [and] I would throw up and it would just be blood and it was something that I realized if I don't stop this, I am going to die."

The former Disney star's shocking revelations came just days after she insisted she wasn't angry with her ex-boyfriend Joe Jonas, 24, for penning an article earlier this month about his life, in which he shared intimate details about her drug problem for the first time.