Many of Andrew Marr's colleagues in the media took to Twitter to express their sympathy.
Fellow BBC politics presenter Andrew Neil wrote:
Very distressed to hear news about Andrew Marr. Best wishes for full and speedy recovery.
Guardian columnist Polly Toynbee tweeted:
Andrew Marr, renaissance man, polymath,wise commentator,painter,runner,brilliant cook - and ace editor.Get well soon.Needed in public life.
Former Tory MP Louise Mensch said:
More top news
A son paid off his parents' mortgage for Christmas - reducing them to tears.
Intruders killed an eight-week-old puppy during a failed attempt to steal from a house in East Lothian, police have said.
It will be a cold day today, with temperatures dipping below freezing shortly after dark.