Charles Manson is in the hospital and, as one source familiar with his situation tells TMZ, "it's not going to get any better for him."

We're told Manson was rushed to a Bakersfield hospital 3 days ago, and has been wheeled around on a gurney for various treatments ... escorted by 5 uniformed cops.

We're told the 83-year-old Manson, who lays still covered in blankets, looks ashen.

Our sources say Manson's health has been steadily deteriorating and, as it was put to us, "It's just a matter of time."