Sir Elton John has said he felt it was necessary to open up about his recovery from cancer because "nobody knew" how close he came to dying.
The music star recently revealed that he was successfully treated for prostate cancer two years ago, having opted to undergo surgery rather than chemotherapy, but that he was later "24 hours from death" after contracting an infection.
The 72-year-old made the revelation in his new memoir, Me, which has been serialised in the Daily Mail.
He wrote that he spent 11 days in hospital after lying awake at night "wondering if I was going to die".
Of his decision to talk about his near-death experience, Sir Elton told Smooth Radio: "I've had a lot of physical things happen to me in the last five years and it hasn't been pleasant, but I got through them and I'm very lucky to have gotten through them.
"But, you just have to grin and bear it and it's that stiff upper lip thing, but I didn't want to say to people 'I've got cancer' or, you know, 'I'm 20 minutes from dying'.
"It was necessary to write in the book because nobody knew about it.
"Nobody knew of how close I was to death with the infection, nobody knew I had cancer but, in the book, I couldn't write it without it.
"I went through a lot of pain and it took me seven weeks after the infection to get back to normal."
He added: "But I still did 96 shows that year."
Sir Elton said he is "pretty stoic when it comes to pain", and that he tried to see "the funny side of it all as well".
"I mean, I'm walking across the stage, fist pumping and waving to the audience and, you know, I'm urinating in my trousers and I just think, if people only knew what's going on, they might not be so enthusiastic," he said.
"But, you have to have a sense of humour about everything in life and I just thought 'What am I gonna do? Go back to the hotel room and be in pain? I might as well do an hour and a half on stage here and take my mind off it.'"
The Rocket Man singer added: "I'm super-fit, I'm super-lucky, I'm, you know ... there's hardly any of me left – there's no tonsils, there's no prostate, there's been kidney stones flying out.
"You know, there's no appendix, there's no hair ... What can I tell you? I am just a shell of a man."
Sir Elton previously revealed that his health concerns encouraged his decision to retire from touring so he could spend more time with husband David Furnish and their sons, Zachary and Elijah.
The interview with Sir Elton John by Smooth Radio's Angie Greaves will air at 4pm on Sunday October 13 on Smooth Radio.