Green Day frontman Billie Joe Armstrong slogged so hard on their new album that he almost ended up in hospital.

'21st Century Breakdown' is the first album in five years from the US rockers — Billie Joe, bassist Mike Dirnt and drummer Tre Cool since multiplatinum hit 'American Idiot.'

Billie Joe said: “This is the album that could have killed us. We had set the bar so high with American Idiot.

“We all became sick as dogs. I was close to being hospitalised but they caught me in time. I had the boogie woogie flu.”

The epic album is split into three — Heroes And Cons, Charlatans And Saints, and Horseshoes And Handgrenades.

It follows a young couple as they negotiate modern life. But the title could also refer to Billie Joe’s struggles as a 21st-Century songwriter.

He said: “I got a BlackBerry and started to write down every idea for a lyric on it.

“I had many a sleepless night where I’d get something and have to get up and tap it into my BlackBerry.”

The album is out May 15.

Watch the video for Green Day's 'Wake Me Up When September Ends' below: