"Kanye will be in the hospital for Thanksgiving and isn't leaving," a source said.
West's wife, Kim Kardashian West, flew from New York to Los Angeles to be with her husband, and the source says she "has barely left his side."
Kardashian West was scheduled to make her first public appearance since being robbed at gunpoint in Paris, as the reality star was planning to attend the Angel Ball in New York on Monday before learning of West's hospitalization.
"Kim has been very concerned and supportive," the source added. "Seeing Kanye like this is scary for her."
West was reportedly hospitalized after authorities were called to his trainer Harley Pasternak's home after the rapper began behaving erratically. It has been confirmed that West is not under a 5150 hold, which allows patients to be involuntarily admitted to hospitals for mental illness.
Insiders say West was hospitalized for exhaustion and extreme stress, and the rapper had previously been displaying erratic behavior during several dates of his Saint Pablo tour, most recently going on a rant about Jay-Z and Beyonce at his show in Sancramento, California Saturday night.