On Monday night, the worryingly slimmed-down star, 49, began "shaking" and "acting like she was suffering from a seizure," reports E! News. A female friend who was visiting Demi's home called 911, and paramedics eventually transported her to a local hospital.
Radar Online also diagnoses a seizure, with a source suggesting, "She has not taken care of her health at all lately and has lost a ton of weight."
E! adds that the actress's inner circle has been concerned about her increasingly attenuated appearance, which seemed to get worse after she pulled the plug on her six-year marriage to Ashton Kutcher in November.
According to TMZ, which first reported Demi's hospitalization, she's receiving treatment for "substance abuse" issues, and claims one of the substances involved is nitrous oxide, known to the college crowd as "whip-its."
A friend says she "lapsed into semi-consciousness" after allegedly inhaling a "dangerous amount" of nitrous.
But were other substances involved too? Keep reading ...