The Wanted's Max George shares update on his heart condition from hospital

Singer Max George is opening up about a health issue that he says will keep him in the hospital through the holidays.

George, formerly a member of Britpop boy band The Wanted, has been hospitalized since last week with a heart condition. Over the weekend, George shared an update on his Instagram Story saying that they've determined he has "an issue with the bottom part of my heart. It's called a block."

"Until I have further tests we don't know what caused it," he added. "We've canceled out a few things - alcohol, for example. I haven't had a drink for four-and-a-half years so it's not that. It's a bit of a mystery, really."

George said he may need a pacemaker, which is a small, battery-powered device that monitors the heart and prevents it from beating too slowly, according to the Mayo Clinic.

CNN reached out to a representative for George for comment.

George wrote on his Instagram page last week that he went the hospital after feeling "really unwell."

"Unfortunately after some tests they've found that I have some issues with my heart," he wrote on Thursday. "I have a lot more tests to determine the extent of the problems and what surgery I will need to get me back on my feet."

He added that "it's gonna be a difficult few weeks" or months and that he'll be spending Christmas in the hospital.

"Although this is a huge shock and no doubt a setback, it's something I'll take on with all I've got! I count myself very lucky that this was caught when it was," he wrote.

Despite his health setback, George appeared to be in good spirits on Sunday as he was getting ready to watch the Manchester City-Manchester United football match.

"I'm all set for the game," he said in the clip posted to his Instagram story, showing a photo of himself, smiling and wearing a his team's jersey in his hospital bed.