Adele has been sick for weeks

Adele has been battling illness for weeks on the road.

The singer was forced to cancel a second show at Phoenix's Talking Stick Resort Arena in Arizona on Wednesday (17Aug16) after a bad cold left her feeling too ill to perform, but in a video update to fans, posted online, the Rolling in the Deep singer revealed she has been suffering with sickness for an extended period of time.

In an emotional video from her sickbed she said, "Even when I’ve been unwell I’ve been on stage. When I was in Belgium I went on stage and I had terrible diarrhoea and I still went on.

"I’ve had laryngitis, I’ve had the flu, I’ve had all sorts going on onstage... I was severely un-medicated. But I still did the show!"

Adele, who's been trekking around the world for 170 days as part of her Adele Live 2016 concert tour, has a history of scrapping U.S. shows - she cancelled an entire North American tour in 2011 to undergo emergency vocal surgery.

Announcing her decision to scrap the Phoenix show on Wednesday, she posted a video on Instagram just hours before she was slated to hit the stage, and said, "Hello, everyone, specifically everyone in Phoenix, Arizona. I can't do my show tonight, my second show here. I'm really, really sorry. I've had a cold for a couple days, and I've been pushing through it. And I did my show last night, and I loved it. But I pushed too hard and my cold has gotten the better of me. And, as you can hear, even if I did the show, it wouldn't be very good."

"I'm really, really sorry to let anyone down," she continued. "I've enjoyed my tour so much and cancelling shows is not something I want to do... I've been trying to sing all morning, and warming up, and nothing's really happening... It's the last thing I want to do, but I have to look after myself, because I've got so many more shows to do."

She then insisted she would reschedule the show, and "come back and smash it for you".

The Grammy Award winner kicked off the North American leg of her tour in July (16).