George Michael has suffered a series of medical problems since 2011.
The singer, 50, has been out of the spotlight since last year, when he fell out of a car on the M1 motorway and was airlifted to hospital with a head injury.
In 2011 he suffered severe pneumonia which left him temporarily in a coma and meant he needed to undergo a tracheotomy in order to breathe.
He has also battled depression and drug addiction.
More top news
Accused Darren Osborne was a "ticking time-bomb" who had become "obsessed" with Muslims in the weeks before the incident, a court has heard.
Ukip's ruling committee unanimously backed a vote of no confidence in Mr Bolton on Sunday and six key party figures have also resigned.
A much improved day across the UK. Rain spreads in through this evening and overnight with the heaviest bursts across western Scotland.