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:
Joining in the chorus of well-wishers for Andrew #Marr. Hope he has a speedy and full recovery.