The 57-year-old actor needs an aortic valve replacement, Diane Rosen said in a news release. Williams' representatives would not say when the comedian was admitted to the hospital or where.
"I'm so touched by everyone's support and well wishes," Williams said in the statement. "This tour has been amazing fun and I can't wait to get back out on the road after a little tune-up."
Williams was already in Florida when he canceled four shows in the state earlier this week after experiencing shortness of breath.
Former first lady Barbara Bush, 83, was recovering well from her aortic valve surgery this week, her doctors said. Replacement valves are either manmade or made from living tissue from human or animal sources.
Since September, Williams had been on the sold-out, 80-city tour, which is expected to resume in the fall, his publicist said. Tickets will be honored once the new dates are scheduled, or people can contact their place of purchase for refunds.
The Academy Award-winning actor got his start as a standup comedian in the 1970s. His high-energy act led to a guest spot on "Happy Days" as Mork from Ork and later the starring role on "Mork & Mindy."
He has appeared in dozens of feature films - both comedies and dramas - over nearly three decades. He won an Oscar for Best Supporting Actor for his role in the 1997 film "Good Will Hunting." Other notable films include "Dead Poets Society," "Hook," "Mrs. Doubtfire" and Disney's "Aladdin."
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