Around 150,000 people have a stroke each year in the UK with about a quarter of these in people of working age, according to the Stroke Association.
Its director of communications, Joe Korner, said:
We are deeply saddened to hear about Andrew Marr's stroke and our thoughts are with him and his family at this hard time.
A stroke happens in an instant but the effects can often last a lifetime.
However with the right care and support it is possible to make a recovery and return to a life after stroke.
More top news
Investigators have extracted data from the crashed EgyptAir Flight MS804's recorder.
Will Jeremy Corbyn be going anywhere? Not if membership figures are to be believed.
Deputy party leader Tom Watson said that what has happened with Jeremy Corbyn is a "great tragedy".