CHICAGO (CBS)–Demi Lovato was rushed to an L.A. hospital after suffering what appears to be a heroin overdose, according to TMZ. 

TMZ says Lovato was transported from a home in the Hollywood Hills just before noon Tuesday, and is currently being treated. Her condition is unknown.

The pop star 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 six-years sober from alcohol, cocaine and Oxycontin, TMZ reports.

Last month she released a song, “Sober,” where she revealed she had fallen off the wagon.

Lovato 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.