Justin Bieber has shared a topless photo of himself smiling in hospital to assure fans he is bouncing back after collapsing at his concert in London on Thursday (07Mar13).

The singer took to his Instagram blog in the early hours of Friday morning (08Mar13) to share a snap of himself lying topless in his hospital bed wearing headphones.

He captioned the snap, "Gettin better listening to Janice Joplin (sic)."

In a post on his Twitter.com page, he added, "Getting better. Thanks for everyone pulling me thru (through) tonight. Best fans in the world. Figuring out what happened. Thanks for the love."

The singer sparked fears for his health when he fainted backstage during his show at London's O2 Arena. He was given oxygen and took a 20-minute break before taking to the stage again to finish the gig.

His manager Scooter Braun tweeted praise for the 19-year-old star, writing, "Tough kid. Proud night. Once again he always finishes the show. True pro (professional). Now get better and rest up! Strange night but proud... Now get better! Love u (sic) kid... Everyone please give him a little space and he will be ok. I'm sure he appreciates the support."

The pop star is scheduled to continue his Believe Tour in Lisbon, Portugal on Monday (11Mar13).