Elton John has given fans a health update before his ITV concert special. The music legend is set to take the spotlight in An Evening with Elton John and Brandi Carlile, where the pair will perform together and discuss their friendship. On Thursday's (17 April) episode of Good Morning Britain , a pre-recorded clip featuring Elton and Brandi was shown, where they discussed filming the TV special. The 78-year-old star confessed he hadn't been "feeling very well" before stepping on stage and also opened up about his "fear" and "doubt" regarding the ITV show. "I had a lot of fear going into it. A lot of doubt. I wasn't feeling very well," Elton honestly revealed. "But, in the end, the anxiety pushed the energy forward. I don't walk away and let people down." He continued: "I was letting myself down, that was what I was irritable about. I wasn't clicking. Obviously, they filmed everything, I'm glad they did because it was a really, really intense process." Elton and Brandi discussed how they'd adjusted to being constantly filmed, which was a new experience for both of them, reports the Manchester Evening News . Elton mentioned that they had mostly failed to notice the cameras because they were working at such a "ferocious" pace. Elton has been candid about his health struggles in recent years. In 2017, he was diagnosed with prostate cancer and underwent surgery to remove his prostate, but sadly, he contracted an infection after the operation. He's also undergone hip and knee replacements, and in 2021, a fall that affected his hip forced him to delay his global tour. In addition, Elton has been grappling with vision issues. After a "severe eye infection" he picked up during a getaway in France, he revealed last year that his sight had dwindled to "limited vision". Now, the star is legally blind in his right eye. He discussed his visual impairment with The Times: "I can see you, but I can't see TV, I can't read. I can't see my boys playing rugby and soccer, and it has been a very stressful time because I'm used to soaking it all up. "It's distressing. You get emotional, but you have to get used to it because I'm lucky to have the life I have." Good Morning Britain airs on weekdays at 6am on ITV1. An Evening with Elton John and Brandi Carlile will air on ITV1 on 19 April at 9.05pm