Demi Lovato, the American actress and singer songwriter has admittesd she was crippled by nerves when she recently made a guest appearance on the hit US TV show Grey's Anatomy.

Speaking in La the actress said "I went in there and I was really nervous because not only is it my favorite show of all time, but I know every single character by doctor names and not actor names."

The Texan really enjoyed her experience on the show and admits that she tried to hard to focus on her performance.

"Working with the cast was amazing, I felt really comfortable there, but I wanted to do my best,"  she said.

Jessica Capshaw, who plays Dr Arizona Robbins took Demi under her wing and put her at ease. "I really appreciated the way the actors treated me on set. Jessie was such a sweetheart and everyone was really nice," she said.

The Disney star admitted that she found her role challenging as she had to protray a sick patient with an ailing condition. After her experience working on the hit hospital series the 18-year-old hasn't ruled out a career in drama.

"I always started off in acting classes where I was the one kid doing scenes from Girl Interrupted so maybe one day I'll end up doing dramas," she said.