Ramis was known as much for his off-screen work -- writing the "Ghostbusters" films, along with "Groundhog Day" and "Analyze This" -- as he was for playing Dr. Egon Spengler in front of the camera.
Ramis was surrounded by family in his Chicago home, where he's lived since 1996, when he died early this morning from complications of autoimmune inflammatory vasculitis, his wife Erica Mann Ramis told the Chicago Tribune.
His rare disease involved a swelling of the blood vessels and the report adds that his health issues began in 2010. His condition was so bad in the past, the actor/writer/director had to relearn to walk.
"His creativity, compassion, intelligence, humor and spirit will be missed by all who knew and loved him," read a press release from his agency.
Ramis was a Chicago native and earned a bachelor's degree from Washington University in St. Louis, MO. He got his start in the late 1960's at Chicago's Second City theater troupe.
His big break came when he penned "National Lampoon's Animal House" in 1978. His directorial debut came in 1980 with "Caddyshack." His latest work was for a 2009 movie "Year One," in which he wrote, directed and was featured in alongside Jack Black and Olivia Wilde. His "Ghostbusters" co-star, Dan Aykroyd, also told ABC News last spring that "Ghostbusters 3" could film this year, and that Ramis was "in on it."
Ramis is survived by his wife Erica, sons Julian and Daniel, daughter Violet and two grandchildren.