UPDATE: Demi's aunt, Kerissa Dunn, posted on social media that Demi is "awake and responsive."
Demi Lovato was rushed to an L.A. hospital after suffering what appears to be a heroin overdose.
Sources say Demi was transported by ambulance from a home in the Hollywood Hills just before noon Tuesday, and is currently being treated. We do not know her condition.
Demi has fought substance abuse for years ... at one point she lived in a sober living home after getting released from a treatment center. She had been 6 years sober from alcohol, cocaine and Oxycontin.
Last month she released a song called "Sober" where she revealed she had fallen off the wagon.
Demi just performed on Sunday at the California Mid-State Fair in Paso Robles with Iggy Azalea.
She was scheduled to go on the road this week for an upcoming show in Atlantic City, but sources say she's been struggling.
Law enforcement sources say Demi was treated with Narcan which is an emergency treatment for narcotic overdoses -- at her home. in the Hollywood Hills.
Demi was out Monday night celebrating a friend's birthday in West Hollywood, and we're told she posted photos on her private Instagram of herself and others in the group. She seemed happy in the pics.