According to TMZ, Paris Jackson, 15, was carried out of her Calabasas family home on a stretcher at around 02:00 by paramedics and taken to a nearby hospital, after a 911 call was made at 01:27.
The caller had reported a possible overdose, TMZ said, although a source said there were multiple cuts on one of her wrists.
Jackson also posted the following tweets on Tuesday: "I wonder why tears are salty? and yesterday, all my troubles seemed so far away now it looks as though they're here to stay."
Sources told CNN Jackson was doing "OK".