By the TMZ Staff
Demi Lovato was rushed to an L.A. hospital after suffering what appears to be a heroin overdose ... law enforcement tells TMZ.
Our sources say Demi was transported 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 cocaine.
Last month she released a song called "Sober" where she revealed she had fallen off the wagon.
Story developing ...