She is stable, conscious and breathing, the official said. TMZ originally reported the 25-year-old singer is being treated for a heroin overdose, but a source later told ET Canada that is not necessarily the case.
A male then spoke with the operator and says "We heard the sirens".
The singer remains in a Los Angeles hospital, where her ex-boyfriend, actor Wilmer Valderrama visited her on Wednesday.
Lovato, who turns 26 next month, said in March that she was celebrating six years of sobriety.
'The overdose has been a wake-up call to Demi that she needs to get more serious about her sobriety and is telling friends and family she will do everything it takes to get back to the awesome place she was in before she slipped'.
"[She] has found enormous success by addressing those issues, and not only addressing them when they were still fresh, but also continuing to speak about them as she had been sober for years". On the song "Sober", she sings the lyrics: "Momma, I'm so sorry I'm not sober anymore/And daddy please forgive me for the drinks spilled on the floor".
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The pair attended the Met Gala together in 2017, and are said to have stayed in touch after becoming close previous year . Things took a serious turn when Chopra attended a wedding in Jonas' family and got introduced to his folks.
The "Skyscraper" singer is "grateful to be alive" after her brush with death but doubts are being raised about whether she really wants to go back to rehab, People Magazine Music Editor Janine Rubenstein said. "Her family and friends, who weren't involved, fear she's been hanging with people who support her drug habit".
Lovato started as a child star on the series "Barney & Friends, " later breaking through as a teen on the Disney Channel film "Camp Rock" and the network series "Sonny With a Chance". She will be leaving the hospital and heading straight to rehab.
He asks her: "Are you with the patient now?"
She later had a recurring role on the Fox series "Glee" and served as a judge on the reality singing competition "The X-Factor" for two seasons.
This story was first published on CNN.com, "What Demi Lovato has said about sobriety and mental health".
She last performed July 22 at the California Mid-State Fair in Paso Robles, Calif.