Demi Lovato is fearful of fan gatherings because some weirdos she has met backstage and at awards shows in the past have left her fearing for her safety.

The Skyscraper singer reveals she has developed a phobia of big meet-and-greets thanks to devotees who got too close and started behaving oddly.

She tells Nylon magazine, "Sometimes a fan will come up and automatically put their arms around me and I just shut down and start hyperventilating.

"I don't want to sound like a d**k or a diva, but I really do have anxiety problems. If I get stuck in a crowd, I'll start to think, 'Oh my God, I'm going to die! Something's going to go wrong and someone's going to stab me'.

"There was a time when people started trying to kiss me, or creeps would buy backstage passes and reach for my face and try to make out with me. That was completely violating, and ever since then, I always fear what someone is going to do when they come up to me."