Ryan Reynolds: I got insomnia and a bald spot while filming 'Buried'

Ryan Reynolds, who was recently cast as superhero Green Lantern, says playing a truck driver trapped inside a coffin in his new film Buried was more physically and emotionally grueling than he had ever imagined.

During the intense filming, Reynolds, 33, struggled with insomnia, panic attacks and even got a small stress-induced bald spot on the back of his head.

'EMOTIONAL + PHYSICAL SCARS'

"All of the physical injuries are like souvenirs," Ryan tells Parade. "But the emotional stuff is harder. When you're spending 17 straight days in a heightened state of anxiety and panic, it's not very good for your nervous system, so you walk away pretty jittery.

I definitely struggled with a lot of insomnia when I was working on this film and that was something that was new to me."

In Buried, Reynolds plays a U.S. truck driver in Iraq who gets trapped inside a coffin with only a cell phone and a lighter.

"I definitely felt like I emerged from the box as a different person than the one that went in," Ryan recounts. "For all of the difficulties and the challenges in shooting a movie as different as this, it was a great experience.

"Anything at the time that I thought was insurmountable or incredibly difficult, the scars and things, are just spoils of war."

'GREEN LANTERN WILL BE OFF THE CHARTS'

The athletic 6'3" Canadian hottie, whose legendary discipline enabled him to transform his body into a lean, mean fighting machine for Blade Trinity (2004) and X-Men Origins: Wolverine (2009), says shooting inside an enclosed coffin gave him some minor claustrophobia.

"Certainly, after shooting I walked away with a new appreciation for claustrophobes," says Ryan.

"The movie isn't just something you watch with your eyes, you feel it with your bones and your heart and your skin and your muscles; it's a full body experience and that's something that I think rarely comes along nowadays in a movie-going experience."

Meanwhile, for his next role as the Green Lantern, Reynolds promises audiences an incredible action movie.

"Fans can expect a movie that has a scope and a scale unlike anything else," he says. "I think of it as Star Wars in the DC Comics universe. I was blown away just visiting the art department on a movie like that; they should just do a film on that.

"It's like a trip to an amusement park that you wished existed."